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Guru Search Results: 177 matches were found

Tuesday, March 29, 2005 #6874
Hi Guru This is the first time i ask you, i work for a local television and i want to know the right time when we dicide that a program is "save", the program must have some evaluation and when we say that a program must be stopped... is there any formula that can explain how we take care that situation with the right way

The Media Guru Answers(Tuesday, March 29, 2005 ):
The Guru isn't sure he understands your question, but it does not seem to be a Media planning/Media buying/Media research/Media department management question.


Tuesday, February 22, 2005 #6808
My media department often compiles "media" market profiles for clients opening new locations/stores. Within this profile we include estimated TV CPP's by daypart pulled from SQAD and a daypart mix by percent (established by past market buys). This daypart mix percentage is then multiplied by the estimated daypart CPP, the result of each daypart is then added and the total is called the "weighted CPP" -- is this right / real? I've looked all over your archives, in glossaries, reviewed formulas and beyond to find out more about "weighted CPPs." Please enlighten. Thanks!

The Media Guru Answers(Wednesday, February 23, 2005 ):
This is right if your weight is percent of spending, wrong if your weight is percent of GRPs.

It would also be be preferable to incorporate the index of your CPP buying experience vs SQAD rather than using pure SQAD CPPs.


Wednesday, February 09, 2005 #6787
What is the formula for combining two R&Fs?

The Media Guru Answers(Wednesday, February 09, 2005 ):
Click here to see past Guru responses about "random probability"


Friday, October 15, 2004 #6637
Hi MG ,could you please tell me when a planner decides for a frequency what time limit he takes in to consideration i.e weekly or monthly and is it differnt for print and TV. 2> SECOND thing is there any calculations to split your money across various media I.e certain % in tv , othres in print and out door, thank you and take care

The Media Guru Answers(Sunday, October 17, 2004 ):
In the US, four weeks is the standard period for setting planning frequency goals.

Setting media mix is a complex process including judgement of media effectiveness, copy issues, and target impact. There is no simple formula


Friday, September 10, 2004 #6598
I have overnight household ratings for a program and I want to know ratings for specific demo, say Men 18-49. What is formula to convert HH ratings to M18-49 ratings?

The Media Guru Answers(Saturday, September 11, 2004 ):
The only way to develop a formula for this purpose is to have past comparisons of actual HH and demo ratings from which to develop a factor.

So for example, if in the past, you found that an overnight program had a HH rating of 2.0 and a M18-49 rating of 1.2 then the factor would be 0.6 (1.2 ÷ 2.0) You could develop factorsa like this for program types or other broad groups with which you work.


Tuesday, August 31, 2004 #6583
Dear Guru, Can you once and for all please give the mathmatics involved to calculate a local r&f into a national r&f, and vice versa. If I am mixing a national schedule into a local market, will the GRP's remain the same? If not, how is it cacluated? Thanks in advance

The Media Guru Answers(Tuesday, August 31, 2004 ):
Local to national is simple arithmetic:

Local reach X % US coverage translates Rreach and GRP to national.

E.g. if you have a Reach / Frequency / GRP of
70 / 4.0 / 280 in a market which is 10% of the US, then national reach is
7 / 4.0 / 28. Note that frequency is NOT recalculated, it is simply the same. In most cases, this doesn't make a difference, but when it does, keep the original frequency. This is because it is a count rather than a percentage. So the same people that were reached, even when expressed as a percentage of a different universe, simply experience the number of exposures originally calculated.

National to local however, invloves estimation or measurement as much as arithmetic: If you have a schedule delivering a national R/F/GRP of
70 / 4.0 / 280, then you may estimate that its local delivery is
70 / 4.0 / 280, because, by defintion, that is the average reach across markets. However, various vehicles have differences in market-by-market audience, and if you have a specific market in mind, you can get the actual value of the schedule's delivery in the designated market. Then reach and frequency can be calculated for the market using whatever R&F model you have at hand, or perhaps using GRP delivery indices established in past experience. A delivery index would apply only to the GRPs; reach grows along a "curve" and would not vary in a linear fashion proportionately to the variations in individual vehicle audiences.


Thursday, July 01, 2004 #6525
I recently encountered a local radio sales rep who was quoting from and distributing "Secret formulas of The Wizard of Ads," a book by Roy Williams. The resulting proposals from this sales rep. were atrocious. Are you able to comment on this author or book (supposedly a #1 Bestseller of the Wallstreet Journal?

The Media Guru Answers(Friday, July 02, 2004 ):
The Guru is not familiar with Roy Williams. What may be gleaned from his web site and reviews at Amazon.com does not incline the Guru to expect media planning applications.


Thursday, May 20, 2004 #6500
Using the OTS formula (GRP/Net Reach), if we set an OTS target with a predetermined reach, can we arrive at the required GRP for differrent OTS targets. Why effective frequency is more popular over OTS when setting frequency objective. In my experience we need to achieve more GRP's to achieve a predetermined reach for an effective frequency over OTS target, any reason for that methamatical relationship.

The Media Guru Answers(Thursday, May 20, 2004 ):
As a matter of simple arithmetic, Reach and GRP are inextricably linked by a multiplying factor which can just as readily be effective frequency. This does not mean that you can set any reach goal at random and assume a given GRP number will relate back with a specifc OTS. Different mixes of dayparts and media elements have different capabilities in reach / effective frequency generation.

Why more GRP for an effective reach level? Again, simple arithmetic explains it. "Reach" in an ordinary "reach and frequency" calculation, means reach 1 or more times. In other words, a frequency of 1 is treated as "effective." Typically, when we talk about "effective reach" we are working on an assumption that 3 or more frequency is needed for effective communications so that only those reached at least 3 times count. Naturally, more GRP are needed to get a given reach 3 tiems than only once.


Wednesday, March 10, 2004 #6414
Dear Guru: I am a pharmaceutical sales rep who is VERY interested in moving into ad sales. It was recommended to me by a current ad salesman that I start in ad buying. It appears that one of the basic tools I will need to make this transition is media math. Where can I pick this up? Is there a book or course or place I can do some self-study available? Thanks for your advice!

The Media Guru Answers(Wednesday, March 10, 2004 ):
See See AMIC Bookstore (in association with Amazon.com) or click here to see past Guru responses with media formulae


Saturday, March 06, 2004 #6403
Hi Guru, I have a question. What's the difference between a frequency plan vs. a reach plan? How would you go about putting together a reach plan if needed? Are there any formulas or anything that you need to plug in to determine reach? How do you know what is effective? Please HELP!

The Media Guru Answers(Sunday, March 07, 2004 ):
A reach plan emphasizes reach versus frequency and the frequency plan is the oppposite. That is, a reach plan is designed to deliver is message to the greates number of different people while a frequency plan emphasizes the number of times each person reached is exposed to the message - no matter how many are reached. Reach plans are used when branding or awareness building are the focus. Frequency plans are aimed at more immediate, direct action such as a retail promotion for a limited time sale.

Some media, such as prime time TV and national magazines produce relatively more reach and others, such as radio, online or daily newspapers are better at frequency within a plan.

You need tools of the sort provided by our own Telmar or eTelmar to evaluate reach and frequency.


Saturday, November 29, 2003 #6282
Is there a method for "manually" calculating the reach/frequency of network TV/radio? I know other options exist (Telmar, for example) but would prefer to have my students do it this way if possible.

The Media Guru Answers(Sunday, November 30, 2003 ):
25-30+ years ago, planners worked with tables of GRPs by medium or program frequency, etc, baseds on averages of many fully calculated actual measurements but not full scale calculation, which would involve treating each commerical individually. While there might be some value in learning how to take a set of observations and develop a curve, trying to make these base calculations for each plan seems pointless.

The purely manual calculation is extremely complex. For example, in print, as input, you need average issue audience, duplication between issues of the same publication and duplication between each possible pair of different publications. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables


Tuesday, November 25, 2003 #6274
If a rating point is the percentage of the audience that could see the message, then what is the difference from reach? I work at a small agency, and we have gotten rid of our software. I used to be able to plug a plan in, and it would compute my reach and frequency, based on the ratings. How can I figure this out without software, if I know the rating points and GRP's?

The Media Guru Answers(Friday, November 28, 2003 ):
Each advertising exposure has certain rating points. For a single such exposure, Rating equals Reach.

For a Schedule, each of the various exposures will duplicate a portion of the audience of the other exposures. The sum of the ratings, less the Duplicated audience is the reach. The sum of the ratings is open-ended. Reach can approach - but not exceed - 100% of the target.

The calculation is complex, and software is worthwhile, especially pay-per-use software like our own eTelmar.

For example, in print, as input, you need average issue audience, duplication between issues of the same publication and duplication between each possible pair of different publications. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables.


Friday, September 12, 2003 #6152
Is there any mathematical model to determine to target group of a client?thx..

The Media Guru Answers(Sunday, September 14, 2003 ):
No one set model. If one has segmentation data, the simplest process is to select the narrows group that includes the majority of use as well as having a skew (over-index) to being users.

In other words if women 18-49 are 20% more likely to be users and also account for 60% of use, that is a good target. However if 25-34 represent over 50% of use and have a similar/better liklihood of use, they may be a better target, keeping in mind that messages always "spill" from the designated target to related demographics.


Thursday, July 17, 2003 #6085
I have an $11,000 cable schedule that achieves 182 demo rating points. In Tapscan the Reach and frequency is 12.4 and 14.7 frequency. In Strata the reach and frequency is 73% reach and 2.5 frequency. I think the truth somewhere in between. Tapscan will not share the algorithims (sp)in the formula and I haven't asked STrata. What do you think?

The Media Guru Answers(Saturday, July 19, 2003 ):
The Guru imagines that the discrepancy has two bases:

One: possibly the Tapscan R&F is assuming that the input is cable GRP and the desirted output is total market R&F, while the Strata is calculating only against cable universe. For example if a market's cable penetration is 60%, then 182 cable GRP = 109 total market GRP. 73 cable universe reach = total 44 market reach.

Two: even under these circumstances, the difference should be less. The Guru suspects that dispersion and programming selection inputs differ between the two so that reach isn't calculated the same.


Saturday, June 21, 2003 #6029
Dear Guru, Please help me to clarify these issues : - What CPT and CPM stand for ? - Are the formulas to calculate them as follows : CPT=(Costx1000)/Impression CPM=(Costx1000)/Reach(000) - Impression and Reach in thousand are not the same,are they? Impression include duplication but the reach in thousand does not. Impression = Reach(000)x OTS? - Therefore, there must be different b/w CPT & CPM. But it seems that most books consider them as the same. - GRP = OTS x Reach (%)or GRP = Frequency x Reach (%)? - Does OTS have some meaning of impression? Since these issue confuse me now so much and I current get a stuck in preparing a report. Pls do reply me as soon as possible. Many thanks.

The Media Guru Answers(Saturday, June 21, 2003 ):
You have tangled up several ideas and defintions. In different countries, some of these terms are used differently or not used. For example, in the Guru's base of the U.S., we do not use "opportunities to see (OTS)," and though you may be in Thailand, the Guru will not assume so.

CPM stands for cost per thousand impressions; the "M" is the Roman numeral M, meaning one thousand. CPT is not familiar in the US, but is probably another indicator of Cost per Thousand impressions.

The Guru most often sees "OTS" used as equivalent to "impressions" but sometimes as a reference to average frequency, so here are the simplest definitions.

"Impressions" are the number of advertising exposures, i.e. the number of different people exposed to advertising times the average number of occasions on which they are exposed. Thus, duplication is included.

"number of different people exposed" is equivalent to "reach."

"Number of occasions on which they are exposed" is equivalent to "frequency."

CPM is cost of advertising divided by impressions in thousands. Reach is not involved.

When reach is expressed as a percentage of a target group, then reach x frequency = GRP.


Tuesday, June 10, 2003 #6006
Dear Guru, I have the circulation figures and the readership duplication percentage of various dailies. How can I calculate the net reach? What are the other variables required to calculate net reach? Thanx, Toolie, Bangladesh.

The Media Guru Answers(Sunday, June 15, 2003 ):
You need a computer with software such as that offered by Telmar.

The calculation is extremely complex. For example, in print, as input, you need average issue audience, duplication between issues of the same publication and duplication between each possible pair of different publications. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables


Thursday, June 05, 2003 #5997
net to gross

The Media Guru Answers(Saturday, June 07, 2003 ):
Net is gross less agency commission. In the traditional formula:

Net is 85% of Gross.
Gross is 117.65% of net.


Thursday, May 29, 2003 #5984
Want to know the calculation of different GRPs to get required reach on 2+ or 3+ OTS e.g. on 400 GRPs gets 60% reach on 3+ OTS

The Media Guru Answers(Saturday, May 31, 2003 ):
You need a computer with software such as that offered by Telmar.

The calculation is extremely complex. For example, in print, as input, you need average issue audience, duplication between issues of the same publication and duplication between each possible pair of different publications. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables


Thursday, May 29, 2003 #5983
what is the formula or how can we calculate the recall impact or residual impact after a TV campaign

The Media Guru Answers(Saturday, May 31, 2003 ):
Recall is not a factor of media so much as an artifact of the power of the creative. In general, some formulae show a loss of approximately 10% of the preceding week's ad awareness level for each week with no new activity.


Thursday, May 15, 2003 #5974
I can use random probability to calculate reach. Is there any way I can create a complete frquency distribution? For instance, Is it correct to add up probabilities for an individual for 4 publications (Say 0.75, 0.75, 0.5 and 0.25) and say that frequency for the person is 2.25?

The Media Guru Answers(Sunday, May 18, 2003 ):
The Guru follows neither your math nor your logic here.

If your example means the the indivisual has a 75% chance of reading the first publication, etc how would that give the person a 2.25 frequency for the 4? You are working with almost unrelated data, not to mention the overstatement of random probability in calculating reach of related media. Further, frequency distribution deals with the numbers of persons who experienced each integral frequency, i.e. how many had one exposure, how many had two exposures. No individual may have a fractional exosure.


Friday, May 09, 2003 #5964
Dear Guru Would be interested in knowing if you have any info on online advertising models for financial clients. Any iformation pertaning to the approach for online advertising for financial clients would be welcome Thanks in Advance Johann

The Media Guru Answers(Sunday, May 11, 2003 ):
Sometimes the Guru wonders at the use of the buzzword "model," apparently meant to make an approach seem formularized. A "reach model," for instance, is a mathematical formula meant to take variables and produce a reach number based on past variables that actually produced a measured reach result. The intended result of a media plan is not so quantifiable when you specify that it is for a particular category. The key is the result intended, this will change according to the narrow category as well as other factors.

A promotional plan to sell bonds to consumers would be quite different than a branding plan for a full service "big 5" accounting firm.

The "model" if any is based on consideration of goals and strategies such as target, and communication strategies. See the Guru's Parts of a Media Plan.


Friday, April 25, 2003 #5950
Dear Guru, In response to your answer of question: Tuesday, April 22, 2003 #5945. I am grateful for this free service and respect your answers. However, your response, “How did they determine that people who have injuries will watch these programs? HAve they looked at / understood reach and frequency, IF this is the right programming?” This doesn’t answer my question. Since their campaign uses a phone number and they get immediate response to their spots, we know the programs they are buying contain their prospects. My point is, they over-advertise in the same area day in, day out, week in, week out (my original over-saturation point). The easy way to prove my theory is to have them just cut back a small portion and buy other areas. They are reluctant to do so without other proof, first. So, my original question stands: How do you determine (using media formulas) that an advertiser has oversaturated a day part? Thanks!

The Media Guru Answers(Saturday, April 26, 2003 ):
The simple approach, based on media formulae is to look for the point where the reach curve flattens (around 80% in the example below). This is where added GRP cease to add enough reach to be worthwhile, generally. But, your issue is one of definiton: What is "oversaturated?" In direct response terms, it's the point where response drops below an acceptable return on investment -- and apparently that has not happened. You would like to experiment with something new, which you apparently believe could have a greater ROI. If there has been any slackening in the response rate, that might justify a test.


Wednesday, April 23, 2003 #5947
Is there any way to determine reach and frequency for a television or radio schedule if the only variables you have are cost and grps?

The Media Guru Answers(Thursday, April 24, 2003 ):
Aside from how many GRPs are affordable, cost has absolutely no bearing on reach and frequency.

GRPs can give a rough estimate if you have tables or formulae of general results, and GRPs by daypart / station / program can be all the input you need if you have the right software or formulae.


Tuesday, April 22, 2003 #5944
For Nielsen ratings, is there a formula to adjust ratings from market to market? I bought a sports program that ran out of sweep and now I have to adjust it to the market that had a sweep book.

The Media Guru Answers(Saturday, April 26, 2003 ):
Do you mean to adjust to a different market or to a different time of year?

If you have other data from the markets, an index of average performance may be developed. For other times, one can average betwenn the adjacent, surrounding sweeps. But sports and specials can be tricky. The World Series occurs between sweeps, but will do better than the preceeding and following sweeps for the time period, In such a case, use the relationship between these periods and the actual dates based on the continuous, national data.


Friday, April 04, 2003 #5918
How are the overall reach and frequencies derived in a buying program for a particular flight? It is not a sum of the r/f for individual stations, or an average thereof. Is there a formula for this?

The Media Guru Answers(Saturday, April 05, 2003 ):
The reach of each media vehicle must be combined with the others in a way that accounts for duplication.

You need a computer with software such as that offered by Telmar.

The calculation is extremely complex. For example, in print, as input, you need average issue audience, duplication between issues of the same publication and duplication between each possible pair of different publications. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables


Saturday, February 15, 2003 #5841
Can you please tell me how to do the Sainsbury formula in order to calculate campaign reach & frequency?

The Media Guru Answers(Monday, February 17, 2003 ):
Click here to see past Guru responses about Sainsbury.

To do the kind of calculation you probably want, you need a computer with software such as that offered by Telmar.

The calculation is extremely complex. For example, in print, as input, you need average issue audience, duplication between issues of the same publication and duplication between each possible pair of different publications. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables


Friday, February 14, 2003 #5838
I am working on creating a hypothetical media plan for a class project, which entails targeting adults age 18-34 years of age, for a new product. I am lost as to how to set Reach Frequency goals, and then once I formulate my plan, how do I calculate the actual reach? Also, how do I figure out cost per point for network tv late fringe and cable tv? Is there a guide that could help me estimate?

The Media Guru Answers(Friday, February 14, 2003 ):
Go to the Guru Archives Search Engine. Use "goals" or "calculate" or the other questions as your search terms.


Friday, January 17, 2003 #5741
Guru- What is the formula for figuring reader duplication of two magazines when I know what percent of each read the other?

The Media Guru Answers(Saturday, January 18, 2003 ):
Subtract the net (unduplicated) audience from the gross audience. Divide the result by the gross. The result is percent duplication.


Thursday, January 16, 2003 #5739
I am looking information about the relationship between SWOT analisis and Reach & Frecuency goals. Can you hel me?

The Media Guru Answers(Saturday, January 18, 2003 ):
SWOT is Strengths, Weaknesses, Opportunities and Threats; in other words situation analysis. Reach and frequency describe communications levels. After a SWOT analysis, one might be led to formulate goals and strategies which include R&F goals. There is no direct connection.


Thursday, January 16, 2003 #5734
Last year i worked for a major outdoor contractor, however due to massive downfalls in the UK advertising market, I lost my job. Now, after a break, I am ready to go back into media but this time I want to be in media planning and buying rather than sales. I want to know Guru how creative scope is within these roles? Also, my mathamatical brain is not too hot! how badly will this affect my chances of landing a job?

The Media Guru Answers(Saturday, January 18, 2003 ):
Planning is primarily about ideas, buying about execution, so creativity would logically be more a part of planning.

Buying uses arithmetic, planning uses algebra and statistics, though both do it with computers these days. A good planner might be building models in spreadsheets, which call for some mathematical understanding. mathematical ability is more likely to be an advancement problem issue than a hiring issue. In the Guru's opinion a seller negotiator migh be better suited to convert to buying than to planning.


Monday, January 06, 2003 #5720
We are a small agency who deals primarily in spot buys. I am putting together a network cable TV buy for a client. Network selection is largely based on MRI data against the target. I have R/F goals that were established based on a cursory "borrowed" run on an optimizer program. I know I can ask the networks to run R/F on the schedules I put together, but how can I get a combined R/F on the entire multi-network buy? We don't have a program that does that for network. Is there a formula? Thanks.

The Media Guru Answers(Sunday, January 12, 2003 ):
Networks than can provide R&F runs can provide combined schedules. Systems vary, inout assumptions are important and some networks know how to slant results. Ask more than one network to do the same combinations as a check.

Our own eTelmar system can do R&F on a pay-per-use basis at a nominal cost.


Monday, January 06, 2003 #5719
I want to develop a competency grid for my team consisting of senior media planners and media buyers. I want to develop a grid that addresses key functional and general management competencies for both functions - planning and buying.Both planning and buying members have 4 to 5 years of experience and are part of a single large AOR team( of around 12 members) The idea is to have a list of indicators against each competency domain and get each member to fill up such an assessment grid with evidences.This self assessment will then be validated by a panel consisting of me( their supervisor) and my business manager and his boss-the VP on the business. My question is: A.What FUNCTIONAL domains should be included for 1.planning and 2.buying B.What GENERAL mgmt domains should be included for 1.planning and 2.buying Greatly appreciate your feedback and help Thanks

The Media Guru Answers(Sunday, January 12, 2003 ):
Current business managment theory seems to be gravitating away from these formaularized assessments. If you must, however, the Guru woul look at

Functional:

  • Turning input into goals
  • Setting clear goals
  • Clear and persuasive writing
  • Analytical ability
  • mathematical facitlity
  • Understanding media types
  • Understanding media math

Management:

  • Interpersonal ability with teammates
  • Interpersonal ability with superiors
  • Interpersonal ability with clients
  • Interpersonal ability with vendors
  • Managing subordinates
  • Leadership and teaching
  • Setting and keeping work schedules
  • Appreciating company budget/expense
  • Entrepreneurship
  • Contribution to the bottom line


Tuesday, December 10, 2002 #5671
I am doing a media plan for a global biotech company and they advertise in the major trade and science journals. They gave me geography goals of 65% US, 30% Europe and 5% Japan. Meaning the % of impressions in each region they want to reach. How do I calculate the percent that they are reaching with the current plan? For example, do I just take the Europe circulation of the publication and multiply it by the total number of insertions scheduled for that pub to get the total number of impressions in europe? Media Guru, I need your help, I don't know how I am going to reach 30% in Europe. Thanks so much.

The Media Guru Answers(Sunday, December 15, 2002 ):
If you assume circulation = readers, then your formula works. In most cases, trade media like these won't have any survey-based audience research available. so circulaiton is a good basis.

Obvioulsy, you need to be considering titles published in some of the regions you wish to cover. See PubList


Wednesday, November 13, 2002 #5617
How do you plan or determine the CPP for A35+ when SQAD does not include this demo in their book for TV or radio?

The Media Guru Answers(Sunday, November 17, 2002 ):
Simple algebra will do. For example, assume you do have CPP for A18+ as $100 and for A18-34 as $125.

Recognize that in the real world, different spots might be purchased for these two demos, but we must assume we are dealing with overall averages.

So, the average spot in the mix that produced the two given CPP has a specific cost, let's say it's $500 (you can make up any number here). The CPP for A18+ is $100, so this average spot's rating was 5.0
($500 ÷ $100 CPP = 5.0 Rating.)

The A18-34 rating must be 4.0
($500 ÷ $125CPP = 4.0 rating).

You would also have the market's populations for all three demographics. Let's assume A18+ is 1,000,0000, A18-34 is 700,000 and A35+ is the difference, or 300,000

The spot's A18+ rating of 5.0 means there were 50,000 A18+ viewers (5 rating X 1,000,000 persons 18+). The spot's A18-34 rating of 4.0 means there were 28,000 A18-34 viewers (4 rating x 700,000 universe = 28,000). Therefore, there are 22,000 A35+ viewers (50,000 A18+ viewers minus 28,000 A18-34 viewers leaves 22,000 A35+ viewers).

So A35+ rating = 22,000 viewers ÷ 300,000 universe or 7.3. Therefore A35+ cpp is $500 ÷ 7.3 or $68.49.

If you're doing several dayparts or markets, plugging the basic facts and formulas into a spreadsheet will make it all easy.


Sunday, October 27, 2002 #5586
Dear Guru, Please tell me the methodology for TV planning cost setup.The information please includes: - what are some of elements considered when working out planning cost? - how are the above elements factored into the calculation? - The methodology you developed to arrive at a realistic planning cost (eg. mathematical formula, wighting factors,etc) -anything else that can help and I missed

The Media Guru Answers(Tuesday, November 05, 2002 ):
Planning costs are essentially most recent costs factored for anticipated increases (or decreases). It's a matter of looking at the economy and the media marketplace, more art than science.


Thursday, October 03, 2002 #5542
Dear Guru, We are a company that specializes in large scale video displays, with our focus on the indoor/outdoor LED screen market. We currently provide our services for events and trade shows. We are developing advertising solutions for companies utilizing this LED Screen Technology. What kind of formula should we use to sell airtime? i.e 30-second spot an hour for seven days between the event hours....say 9am-8pm. There are ten sponsors of this event. The event will draw approximately 50,000 people over the seven days. Any help would be greatly appreciated. Regards, Darren

The Media Guru Answers(Sunday, October 06, 2002 ):
Start with outdoor as a model. An average cpm might be $5.00. Perhaps that could double if you have full sound with animation. Perhaps it could double again if the event audience is highly desirable to the advertiser. That would make the price $1000 over the course of the event. Can you also charge for frequency, i.e. once per hour? Remember we just based the audience on the whole event. The audience of a show open 36 hours over three days will average perhaps 2-3000 at a time. Can they all see every commercial? Think about how long each visitor stays and how often they would pay attention to the commercial. An average frequency of two seems generous.


Thursday, September 26, 2002 #5532
How can I calculate reach & frecuency?

The Media Guru Answers(Thursday, September 26, 2002 ):
You need a computer with software such as that offered by Telmar.

The calculation is extremely complex. In print, for example, as input, you need average issue audience, duplication between issues of the same publication and duplication between each possible pair of different publications. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables


Thursday, September 26, 2002 #5531
is there a formula for figuring out what the % of advertising dollars should be compared to projected sales?

The Media Guru Answers(Sunday, September 29, 2002 ):
No.

There are too many factors: category markup, competition, product life cyle, etc, etc.


Tuesday, September 10, 2002 #5510
Several of my AEs INSIST that there is a way to combine different media R/F over different time periods. Can you help me with what to tell them... why it won't work, how it would skew the numbers, etc... so I don't have to fight this fight every few weeks?

The Media Guru Answers(Monday, September 16, 2002 ):
There is a way, mathematically at least. Conceptually, one medium reaches a certain group of people and the other reaches the audience which it reaches. There will be some duplication between these two groups of people reached. Broadly, the difference in time won't cause a major difference in the mathematical results.

The problem is that when planning combined media, we look for cumulative effect on consumer perception. Obviously, it's different when the consumer sees TV alone in February and magazines alone in April, rather than beinbg exposed to both over the same period. The difference is not in reach so much as impact. Perhaps it is important to keep the standard labels on your numbers, i.e. "Average 3 week reach," and "average 4 week frequency." When they don't occur together, the labels need to reflect that fact.


Tuesday, August 20, 2002 #5474
In calculating media commissions, what is the professional terminology that can be used to explain to the client on why the 1.1765 for 15% is used and who developed this formula?

The Media Guru Answers(Tuesday, August 20, 2002 ):
It is merely simple arithmetic. Let us suppose there is a radio spot which costs $100 gross. The net cost of this spot would be $85, after the 15% commission. If you knew only the net and wanted to calculate the gross, 85 x 1.1765 = 100. The basis for why the traditional commission came to be 15% may be lost to the ages.


Friday, August 16, 2002 #5468
I need to know, What is the data that I can use to calculate newspaper reach?

The Media Guru Answers(Friday, August 16, 2002 ):
As in your adjacent query, you need a computer with software such as that offered by Telmar.

The calculation is extremely complex. As input, you need average issue audience, duplication between issues of the same publication and duplication between each possible pair of different publications. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables.

Try The Newspaper Advertising Association for some general estimates.


Thursday, August 15, 2002 #5467
Is there any specific form to estimate print media reach?

The Media Guru Answers(Friday, August 16, 2002 ):
You need a computer with software such as that offered by Telmar.

The calculation is extremely complex. As input, you need average issue audience, duplication between issues of the same publication and duplication between each possible pair of different publications. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables


Friday, August 09, 2002 #5459
Dear Media Guru, is there any clear relation (formula or something) between Effective reach and GRP? For example: if I have to achieve 3+ Reach 60%, how much GRP do I need?

The Media Guru Answers(Saturday, August 10, 2002 ):
Different media and media element mixes yield different results. That is, 100 GRP of radio is different than 100 GRP of TV or newspaper. 100 GRP of daytime TV is different than 100 GRP of Prime and News.

Reach and frequency models can deal with these differences, but there is no one-size-fits-all GRP number for a given effective reach.


Thursday, August 08, 2002 #5458
Dear Guru, I am the marketing director for an 80 unit restaurant chain with locations in 9 DMA's (2 being top 20.) For us to advertise promotions at point levels that increase sales and are within our budget, we have been forced to use a tiering strategy in our media purchases. By this I mean that we determine what type, weight and number of weeks of media each market will receive based on dividing the cost by market by the number of locations. Are there any other formulas or tools we should use to help us with this proces??

The Media Guru Answers(Saturday, August 10, 2002 ):
Your current method assumes that every restaurant is equal in generating sales or profits. You could allocate according to market sales. Or you could account for efficiency: If market A has half the population of market B and each has 10 restaurants, but the cpp is double in B, do you adjust for this, i.e. spend where the dollars give more action?


Thursday, July 25, 2002 #5435
Many years ago I used a formula to measure brand recall on TV. It was called the Zielski Study, and basically you applied a formula to the TV weekly TARP weightings when on air and another formula to current recall % achieved to measure the recall "drop off" factor when off air. You were then able to manage flighting of a TV schedule to either maintain a target recall %, or analyse exactly how many weeks you could be off air before dropping below a nominated recall % and then calculate how many TARPs were required to lift recall to the desired target. You wouldn't happen to have that algebraic formula would you?

The Media Guru Answers(Saturday, July 27, 2002 ):
You seem to be talking of awareness, an aspect of a brand or of advertising, rather than recall, a phenomenon usually attributed to an individual advertisement.

The kink in these formulae is that they seem to be keyed to 100 GRP per week for a brand with established awareness. Click here to see Guru discussion of awareness decline formulae.


Wednesday, July 03, 2002 #5398
how could I create a reach curve if I don´t have any information of "frecuency and reach" available. What kind of assumption should I suppose? Thanks Thanks.

The Media Guru Answers(Friday, July 05, 2002 ):
"Creating a curve" is about graphing some data so that other data can be interpolated. In other words, when you know the reach or frequency from a few different schedules of GRPs, you then can predict the results of others.

Lacking any data, what assumptions might you make?

  • The general shape of a reach curve is more or less like the one shown below

  • Generally, the curve rises rapidly at first and then flattens, because it is 'asymtotic,' in mathematical terms
  • The top of the curve cannot exceed the reach potential of the medium.
  • The starting point will have reach equal to the rating of a single announcement, but the curve is drawn from a (0,0) origin.
  • The smaller the average rating, the slower the rise.
Reach curves are usually created from the frequencies observed in the known schedules, because the graph of frequencies is a straight line, so its 'slope,' to use another mathematical term is easier to deal with.

Reach with no observations is a complex calculation. You need a computer with software such as that offered by Telmar. In one example, as input you need average announcement audience, duplication between announcements of the same vehicle and duplication between each possible pair of different vehicles. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables


Sunday, June 30, 2002 #5387
I'm working in Japan this summer and trying to get as infomration on the effectiveness of advertising and using a mix of media vs. buying only Tv. Are there any statistics on reach and frequency measurements or can you suggest a simple way I can translate the information to my client without getting too technical? - Difficult to cross the language barrier.

The Media Guru Answers(Monday, July 01, 2002 ):
Keep in mind that in different countries and cultures media behave differently, media mix differently and reach/frequency cumes differently. The U.S. Hispanic market's media are very different than U.S. general market media, for example. Therefore, it would be a mistake to think about simply translating U.S. concepts. Basic definitions such as rating or impressions should be safe, but mathematical relationships or impact measures can bne quite different.

Try Japan Marketing Association for some help.


Monday, May 20, 2002 #5293
I'm trying to convert a local media test campaign (TV, Cable and Radio) to national weight levels. Is there a conversion formula to follow for each medium?

The Media Guru Answers(Tuesday, May 21, 2002 ):
The apparently logical formula, based on population percents simply doesn't work because of efficiencies of scale. The relative efficiencies vary from one medium to another. If you don't have some actual costs in each national medium to index against to your local costs, you will have to get them.


Wednesday, February 06, 2002 #5061
I'm looking for some research/formula that will help with determining communications budgets between mass media and direct efforts based on where products are within their lifecycle.

The Media Guru Answers(Sunday, February 10, 2002 ):
Try The Advertising Research Foundation InfoCenter. For details about the InfoCenter, call 212-751-5656, extension 230.


Monday, February 04, 2002 #5050
Is Telmar's multi-basing system the same thing as Fusion? And, if I'm currently doing the random probability formula to get total reach percent, what is the difference between that and Telmars calculations? Thanks.

The Media Guru Answers(Wednesday, February 06, 2002 ):
According to Telmar:
Multibasing preserves the integrity of a survey. It does not ascribe answers, and as such, avoids what we call "regression to the mean", washing away everything to averages. It preserves the leverage of a media element against any target group, not just those that leverage on demographics.

Telmar's R&F formulas use the actual turnover and duplication between media that are inherent in the survey. When there is real data, we use it.


Monday, February 04, 2002 #5049
I am fitting curves on decay data. It was suggested to me to use a beta-binomial distribution as a fit. It's not available in SPSS: where can I get some [free] software? Also, can you give me a layman's description? Also, what does it look like?

The Media Guru Answers(Monday, February 04, 2002 ):
The Guru doubts ther is such software available for free. You need software such as that offered by Telmar.

The calculation is extremely complex. Click here to see an example of the math of the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables


Thursday, January 31, 2002 #5039
calculate reach and frequency

The Media Guru Answers(Thursday, January 31, 2002 ):
You need a computer with software such as that offered by Telmar.

The calculation is extremely complex. As input, you need average issue audience, duplication between issues of the same publication and duplication between each possible pair of different publications. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables


Thursday, January 24, 2002 #5033
Is there any data out there that provides ROI information on Radio/Print/TV/Cable Schedules. Just some basic numbers. For example, we mostly know that direct mail averages about a 2% response. Is there a formula or somewhere I can go to get info for Radio or TV? For example #2 My client is placing a certain number of grps on Radio and wants to know of the people reached, how many will attend the event advertised (like a one day seminar). What they want to know is on average how many people reached respond to an ad (Print/Radio/cable/TV). Any where I can find a rough estimate or some research- This is kind of like the "Ad Effectiveness Lab" that Arbitron is working on , but is not finished with.

The Media Guru Answers(Thursday, January 31, 2002 ):
There are too many variables to generalize. It depends much, much more on the message and product than on the medium. An event is different than a movie, which is different than an inexpensive household product which is purchased frequently, which is different than a big-ticket item bought every few years.

One good resource is an article, "Advertising Wearin and Wearout" in the September/October 1998 Journal of Advertisng Research.

For much more try The Advertising Research Foundation InfoCenter. For details about the InfoCenter, call 212-751-5656, extension 230.


Wednesday, January 23, 2002 #5031
How do you determine the wear-out of a magazine print ad? Is there a formula that can be applied to the number of times you should run a creative unit?

The Media Guru Answers(Thursday, January 31, 2002 ):
Wear out is not a matter of calculation, although some develop rules based on their brands' experience..

Click here to see further Guru comment on wear out.


Wednesday, January 23, 2002 #5030
Hi Mr Guru. Just wondering : in the basic (reachxfrequency)xCPM/1000 formula, I have a question about reach. Are we talking about the number of people who see the ad, or who might see the ad ? E.g. the 500,000 people who drive by a billboard every week, but who don't necessarily see it. Thanks a lot.

The Media Guru Answers(Thursday, January 31, 2002 ):
There is a term - "opportunity to see" - more commonly used in Europe and probably more descriptive than our own "impressions." Each research measurement has a standard for inclusion in the reported audience. For outdoor it may be something like: the number of cars passing a billboard each day time an average of 1.7 passengers per car. In magazine, the number of persons who say they looked into the most recent issue. There are arguements about why each overstates the numbers actually exposed to the ad. However, reach and frequency systems are usually built to deal with the reported audiences fed to them. Most sytems have allowances to adjust inputs or results based on attentiveness, noting or other refinements.


Tuesday, January 22, 2002 #5025
What do I need to calculate reach for print and what is the formula?

The Media Guru Answers(Wednesday, January 23, 2002 ):
You need a computer with software such as that offered by Telmar.

The calculation is extremely complex. As input, you need average issue audience, duplication between issues of the same publication and duplication between each possible pair of different publications. These must be combined using a complex formula such as the Beta-binomial function. There are variants of this formula, which might be preferred, depending on media type and other variables


Thursday, January 03, 2002 #4973
Can you please explain the difference between TV network and spot buying. What is the equivalize and non-equivalize concept. Why is it used in network buying and not in spot(units are not equivalized). Also can you please explain the reweight concept. How do you come up with reweight cpm. Why can you just do a straight year cpm comparison.

The Media Guru Answers(Friday, January 04, 2002 ):
Click here to see past Guru responses about equivalizing. "Why use it?" is a good question regardless of the network versus spot element. The use of equivalence is an artifact of mass buying by corporation wherein large numbers of :15's and :30s are bought but need to be readily comparable. In spot, this type of buying is less common. Also, network :15s are almost alwasy priced at 50% of :30's making equivalence simple. In spot the ratio is usually higher, and inconsistent.

In network, the geography for CPP / CPM is consistent, so that CPP and CPM can be converted back and forth based on simple multiplication or divsion by the relevant demographic universe. In spot however, while CPP is based on the defined DMA (or occasionally metro) geography, CPM is based on impressions generated anywhere, so there is no simple mathematical relationship.

For other network buying concepts use the Go to the Guru Archives Search Engine.


Tuesday, December 11, 2001 #4938
Greetings. You previously answered a question for me regarding calculating R/F for a trade print plan (question #4900). Based on your answer (which included calculating ratings and using industry standard duplication figures), I am calculating overall Reach for each publication and for the entire schedule. Once I have that information (Reach%, Rating%), can you confirm what formula I would use to get the Frequency (both for each publication and for the entire schedule). I have searched many years of your archives and can't find an answer that addresses that specific question. Thanks!

The Media Guru Answers(Tuesday, December 11, 2001 ):
Frequency = GRP ÷ Reach

GRP is the sum of all the Ratings which go into the Reach.

For example, if publication "A" has a 12% rating, three insertions = 36 GRP.

A schedule of 3 times in publication "A," plus 4 times in publication "B," which has a 16% rating = 110 GRP.


Wednesday, November 21, 2001 #4902
We are trying to figure out a gross cpm for a client who we have given a net cpm to. She is looking to compare the two. (I am not speaking in terms of gross/net rate -agency 15%) Here is a scenario that I am trying to figure out: By publication - 439,000 target audience $51,000 FP rate = $116 net cpm. How would we go about getting the gross cpm to compare to this? From a total plan standpoint, we also presented net cpms and the client is looking for a gross cpm for comparison. How exactly would I go about figuring this out?

The Media Guru Answers(Wednesday, November 21, 2001 ):
The Guru does not understand your question. The common definition of the terms gross rate / net rate referes to the difference between a rate including agency commission (traditionally 15%) and a rate not including this commission. This definition would yield a $135.29 gross cpm for $116 net. The only reason the gross would be different would be if there was some other understanding about agency commission / compensation.

The formula to calculate gross cpm, when commission is 15% is:
net cpm ÷ (1 - 0.15).


Tuesday, November 20, 2001 #4900
I am trying to estimate past Reach & Frequency for a transportation trade industry print campaign -- and based on that set R&F goals for 2002. I have gathered the following information: Target universe in US, Asia and Europe; each publication's circulation to that target (where available); duplication (very limited availability of this from these pubs). Given this information, what formula could I use to (gu)estimate Reach & Frequency for this Trade plan? Alternatively, what other measures could I offer to my client to measure a recommended media plans effectiveness (i.e. Competitive SOV)?

The Media Guru Answers(Wednesday, November 21, 2001 ):
The simple formula begins by calculating audience-divided-by-universe to estimate ratings (probability of exposure). Multiplying together all the negative probabilities gives you the reach, disregarding specific duplication. In other words, if you get a rating of 14% of target, the negative probability is 86%. Then, two issues of that publication have a combined negative probability of 0.86 X 0.86 or 0.7396. Thus the probable "reach" is 1 - 0.7386 or 26%. This reflects a rando likelihood of dulication of roughly 14%. In reality, there is more than just this random duplication between two issues of the same trade title, probably 50%+, so a better estimate of the reach would be 14% + 50% of 14%, or 21% reach.

For a good guestimate, combine all your insertions this way, using 60% duplication between repeats in the same title and 30% between different titles. Use judgement about titles from different countries which may have virtually no mutual duplication.

SOV is another comparitive tool. Going beyond relative communication and relative spending gets quite speculative.


Thursday, November 15, 2001 #4894
Will you please explain the math and rationale for equivalizing :15s in broadcast tv? I keep hearing the term, but my buyer couldn't clearly explain it. She also said she didn't believe in doing it. Do you? Thanks as always!

The Media Guru Answers(Thursday, November 15, 2001 ):
Buyers and planners look at this process differently. In actual fact, a :15 and a :30 in the same program have the same audience, but different costs.

To planners the audience is more important, in its relationship to reach, etc.

Buyers, however are more cost and efficiency focused at the program level. They will simplify avails by assignninig everything the :30 price and using a factored audience to reflect the :15 efficiency.


Tuesday, October 30, 2001 #4852
What is the formula or methodology for calculating reach and frequency in print media?

The Media Guru Answers(Tuesday, October 30, 2001 ):
There are various formulas, such as beta bimodal, Metheringham, etc. The complexities call for computeres or a lot of time. Try Telmar or eTelmar.


Thursday, October 11, 2001 #4782
can you show me some of the formulas developed to measure cost per thousand, and other media planning formulas?

The Media Guru Answers(Monday, October 15, 2001 ):
Click here to see Guru discussion of media formulas.


Wednesday, October 03, 2001 #4754
Is there an "equivalancy" formula comparing the effectiveness of one newspaper and and a television commercial that appears "x" times for equal recall?

The Media Guru Answers(Monday, October 08, 2001 ):
No standard formula. Once you set your units, you mught compare awareness or other measures. The right comparison should allow common budgets, not compare unit to unit.


Friday, August 17, 2001 #4663
Love, love, love this site! I think you are providing a wonderful service. I read a recent question which as about an OTS formula (OTC?) I have never heard of this term. Would you tell me what the letters stand for? (I looked in your media terms section, and it is not there.) Thanks,

The Media Guru Answers(Friday, August 17, 2001 ):
Thank you for your kind words.

"OTS" or "opportunities to see" is used differently by various practitioners. One meaning is equivalent to impressions, or the number of exposures of a campaign to individual members of the target demographic; a summing of the audiences of all the advertsing occasions of a campaign. In this sense, "average" is not an appropriate modifier. Others may use the phrase "average OTS" as we in the US use "average frequency."

The term OTS is not commonly used in the US, but is standard in the rest of the English speaking world.


Wednesday, August 15, 2001 #4658
Guru, Could use some help framing questions for my agency relating to the effectiveness of a media campaign. We recently ran a test cell for a new campaign (our first)in which the agency provided information on total TRPs, total reach and total frequency over the life of the test. I need to determine how the frequency builds over time. Are there any formulas/rules of thumb for calculating build over time? If not, what specifically should I ask them for? Thanks.

The Media Guru Answers(Wednesday, August 15, 2001 ):
Reach relates to GRP in a curvilinear function. Frequency relates to GRP in a straight line. This doesn't mean that each week adds the same amount of frequency, merely that it's fairly easy to work with.

The easiest thing however, is probably to ask the agency to calculate cumulative reach and frequency, week by week, over the course of the campaign.


Saturday, August 11, 2001 #4650
can you give me the formulae to calculate the OTS viv a vis competition in the print media.

The Media Guru Answers(Saturday, August 11, 2001 ):
The question isn't quite clear: If you mean the formula to determine what your own OTC goalshould be vis-a-vis competition, it is very simple:
If Y= your goal OTS and
C = competitor's OTS then
Y > C

If you mean a formula to calculate your competitors current OTS, you need to have quantities from reports before you can determine what formulae to apply. For example, do you know spending ($)and average cost per OTS (O)? Then the formula is
$ ÷ OTS


Thursday, July 19, 2001 #4594
Hi Guru, I have a set of queries: 1. What is the difference between program reach and program TVR. 2.How can reach curves be used in planning media 3.What skills apart from negotiation does a media buyer need 4. The gross weight of a tv plan can be a. sum of all spot tvrs b. product of 1+ reach and average ots of the entire plan These values for the same plan are not always equal- why? 5. Why dont u allow advertising on your site? How do you make money from your website currently Please let me know Thanks Ajit

The Media Guru Answers(Thursday, July 19, 2001 ):
Your terminology is a bit different from US usage, but with given assumptions the Guru's answers are as follows:
  1. Assuming "TVR" is rating, program reach and rating are identical for a single ad unit. Reach and ratings accumulate differently because reach discounts audience duplication from one ad unit to the next.
  2. As an example, reach curves show where the reach added by additional advertising in the same medium diminishes and a new medium should be added to the mix to optimize the effect of more spending.
  3. Aside from negotiating skills, a buyer needs good communication skills to convey the benefits of his buys. Otherwise, the skills are the same as any for business, perhaps emphasizing math.
  4. Assuming again that "TVR" is ratings and that "average ots" is average frequeuncy of exposure, then the sum of tvrs must equal the product of 1+ reach and average ots. Any tiny difference will be rounding.
  5. Of course AMIC accepts advertising! Ads do not appear on the Guru's "current answers" page, because it is dynamically generated by scripts, from a data base.


Monday, July 09, 2001 #4563
Increasing Budget and Web Response: Is there research showing that if I double (triple, whatever) an overall promotion budget to drive click-throughs on a Web site, I'll double--or more than double -- the rate? Is there a formula that can be presented to the client. Thanks!

The Media Guru Answers(Wednesday, July 11, 2001 ):
Like the reach curve, "response" functions are typically curvilinear, that is, once they reach a threshold level, each added dollar adds less return than the prior efforts.

As far as research that might yield a formula, try The Internet Advertising Bureau or The Advertising Research Foundation InfoCenter. For details about the InfoCenter, call 212-751-5656, extension 230.


Friday, June 29, 2001 #4538
Hello again, I have two questions about calculating reach and frequency that I have been unable to find in the archives of past responses. Perhaps you can help? 1. I normally use the formula (a+b)-(.a*b) to determine combined reach of two mediums, such as radio and print. How do I calculate the combined reach of more than two? The plan I am working on includes spot TV, spot radio and local newspaper. 2. Is it possible to determine a combined reach for more than one market or should each market be reported separately? In the past, I have provided separate delivery for each market in the same plan with a total number of gross impressions for the whole plan. Is this correct? Thanks in advance!

The Media Guru Answers(Friday, June 29, 2001 ):
1. This common formula is based on an assumption that different media duplicate their audiences according to random probability. Therefore if you follow this assumption, media may be added to combinations of media in a "chain" of the same formula. So, once you have combined TV and Radio, you can use this combination as your "a" and then combine it with newspaper as "b."

2. You can combine reaches across markets by doing a weighted average. Multiply the reach in each market by the percent of U.S. in each market. Add all the products and divide by the sum of the % U.S.


Wednesday, June 06, 2001 #4458
I'm working on a plan that includes cable and network television. I have been asked to present a rational for different schedules on three levels of spending. If i know the programs rating point, the average CPP and the cost per spot, how can I use this information to put together the total reach/frequency of sample schedules. I'm trying to get general information at this point without contacting reps to run several schedules. I need to know how to do the math by hand without a program if it's possible. Thanks

The Media Guru Answers(Wednesday, June 06, 2001 ):
It's no longer really reasonable to do the math by hand. The Guru has described calculating reach by "Random probability" in the past. But the unique duplication patterns within tv schedules need to be accounted for either with tables reflecting many schedules' reaches or computer models.

Our own eTelmar offers low cost, single use, online reach calcuation.

You might try the R&F generator at U. Texas .


Tuesday, May 08, 2001 #4379
Dear Media Guru: Are there any "magic" formulas regarding advertising levels/weights and retail traffic pull through? Please advise. Thank you.

The Media Guru Answers(Tuesday, May 08, 2001 ):
There is no general magic. Individual experience will tell how it works in specific advertisers cases. There may be some ability to generalize within categories, as broad as "upscale restaurant in the NY metro area."


Monday, May 07, 2001 #4375
Is there a formula or program for calculating optimum daypart mix? I am working on a client that has used the same daypart mix for years. I wanted to really put some thought into this plan and not rehash every previous years plan and thought there must be some way to take the MRI information in comparison to the CPP's for each daypart.Please advise. Thank you!

The Media Guru Answers(Saturday, May 12, 2001 ):
This is the task of programs called "optimizers" of which so much has been written. AMIC's sister company, Telmar, offers one called "Transmit".

Also see writings about optimizers in AMICs Ephron on Media area.


Tuesday, March 20, 2001 #4273
Dear Guru, Can you guess at an estimated reach for a 4-week radio schedule at 150 TRP/WK (W2554)? Also, do you happen to know the formula for manually figuring reach/frequency? Thanks for your help!

The Media Guru Answers(Tuesday, March 20, 2001 ):
The formulas for radio reach are enormously complex and must take into account number of stations, daypart mix, average rating and other variables.

Your 600 GRP schedule might generate (roughly) from 35 to 70 reach, depending on these variables.

Click here to see past Guru responses abourt calculating reach.


Monday, March 19, 2001 #4268
This question pertains to new ABC rule which takes effect April 1, whereby newspapers will be able to count as paid circulation any copies that are sold for at least 25 percent of the basic price. I am currently paying $19.20 for my Sunday newspaper subscription. The $19.20 is for 12 issues ($1.60 per issue) of the paper. Cost on newsstand = $1.75 per issue. 12 issues newsstand = $21.00 ($1.75 x 12) 12 issues subscription offer = $19.20 I am now receiving an incentive for 24 weeks of the evening paper (Mon-Sat) --- free subscription for M-Sat for the price of my Sunday sub. Newsstand cost for daily paper = $.50 per issue Based on this the math works out to: $.50 x 72 issues (12 weeks x 6 issues/wk) = $36.00 $1.75 x 12 issues (12 weeks - Sunday) = $21.00 Total Basic Cost = $57.00 Subscription Cost for Sunday + Free Daily = $19.20 $19.20 / $57.00 = $33.7% === Does this mean that the newspaper will be able to count the FREE DAILY PAPER as PAID? Your help is much appreciated.

The Media Guru Answers(Wednesday, March 21, 2001 ):
The Guru believes the answer is no, based on section (d) of the following portion of ABC rules (and allowing for the change to 25%):

(b) Subscription Sales:

(1) On term order for a year the subscription must be paid for at not less than 50 percent of the basic annual price.
(2) In case of a subscription for more than one year the subscription must be paid for at not less than 50 percent of a pro rata of the basic annual price for the period covered by the order.
(3) If the subscription is for a period of less than one year it must be paid for at not less than 50 percent of the basic price for the period offered. If there is no basic price for the period offered it must be paid for at not less than 50 percent of a pro rata of the basic price for the next shorter period. If there is no basic price for the term offered nor for a shorter term it must be paid for at not less than 50 percent of a pro rata of the basic price for the next longer term.
A price for a period of less than one year that is less than a pro rata of the basic annual price shall not be considered a basic price.

. . .

(d) Subscriptions to any publication received as a result of an offer by a publisher that stipulates that part of the subscription term is free will qualify for inclusion in paid circulation only when a contractual agreement exists for the full term of the subscription and is in accord with the provisions of Paragraph (b) above. Without such contractual agreement, those copies which a subscriber is informed are free shall not qualify as paid circulation and instead shall be set up in unpaid circulation.


Tuesday, March 13, 2001 #4250
My ad agency is putting together a media plan for a client. Currently, the client is spending about 15% on radio and 85% budget on broadcast television. I am recommending a combination of radio, cable and broadcast. I am trying to show a combined reach and frequency. I am able to do this for radio and broadcast tv with my media software. How can I add in the reach and frequency of cable (since universes are different)? My cable rep says she can enter my entire schedule (broadcast & cable) to come up with reach and frequency. Is this possible? Won't I be neglect in showing reach to those HH without cable???Please respond ASAP. Thanks!

The Media Guru Answers(Tuesday, March 13, 2001 ):
The Guru can recall when some managers opposed the introduction of computers because people would no longer know basic media math.

Keep in mind that the real story is how many people you reach. Once you determine that, it is simple arithmetic to express that number as a percentage of a target group, as we are used to seeing reach.

It is also standard to show reach within the cable universe and in the remaining U.S. For example, you might show that you reached 75% of the cable universe and 60% of the remaing U.S.

And. . . if the cable universe is 80% of the U.S. then your average U.S. reach is 72%

0.8 x 75
+ 0.2 x 60 =
72


Friday, February 23, 2001 #4202
We are doing the planning for an acount in a market we have not previously bought. The demo is Adults 25-54. What formula is used for establishing the weight distribution per daypart. If we are asked to buy 150 points per week how do we determine what the percent of each daypart.

The Media Guru Answers(Sunday, February 25, 2001 ):
This depends on plan goals. If reach is the main goal, then you can examine a variety of mixes of weight to see the best reach available within the budget. The same technique works if the goal is effective reach or frequency.

In all likelihood, starting with about 20% - 25% in each of 4 or 5 dayparts and changing mixes in 5% increments, you will find very little difference except by adding or deleting prime time totally.

If impressions weight is the key, then just buy according to best efficiency, once your reach minimum, if any, has been met.


Thursday, February 01, 2001 #4145
Is there a tool or a formula that can effectively guestimate the number of leads expected from an advertising campaign?

The Media Guru Answers(Saturday, February 03, 2001 ):
The only valid tool is past experience with similar campaigns. In direct response the importance of the content (offer, price and pitch) means that media factors are outweighted as predictability issues.


Tuesday, January 30, 2001 #4138
Hi, Currently I'm preparing a business plan for a startup. I'm considering radio and print advertising in the top 50 markets. I will eventually hire an agency to work out all the math. But for the sake of projecting marketing expense, is there a way I can show "so many spots/print ads in so many main stations/magazines in the top 50 markets for a total budget of $500,000? I'll be happy as long as I can quote average rates for radio spots and print ads from reliable sources.

The Media Guru Answers(Wednesday, January 31, 2001 ):
It's easier if you think of radio in GRP terms. Then you can look at average rates in SQAD and do your calculations.

The Guru does not think you will find local magazines, other than Sunday newspaper supplements, in most of those markets.

Newspaper rates can be found at Media Passage.


Saturday, January 27, 2001 #4129
Dear Guru, I'm looking for information concerning Fair Share in television. Is there any other way to tell how much % one should invest in a television channel? Since the Fair Share formula is taking the amount of breaks one channel has into account, the more breaks a channel has the more % of the media budget will go to this channel. So even if a channel has let's say 30% of bad breaks (not viewed by the audience) this channel will score good in terms of Fair Share. What's your opinion on this? Thanks in advance!

The Media Guru Answers(Sunday, January 28, 2001 ):
The Guru does not support buying based on stations' share of viewing. This practice undercuts the point of negotiation. If a station sales person thinks he/she is entitled to "X" share of your budget, then the incentive is to keep unit prices high.

It is even less logical to reward a station for having more inventory, which is a disincentive to viewing.

Share might be a starting point. Efficiency, reach/rating and composition should be essential adjuctments from there, and number of breaks of little or no impact.


Wednesday, January 17, 2001 #4103
When was the last time the Reach & Frequency Curve was updated? And what is the significance of that?

The Media Guru Answers(Wednesday, January 17, 2001 ):
Reach, as we use it, is a mathematical calculation, based on average performance of actual schedules similar to the ones for which we are trying to estimate audience accumulation for a plan. A large number of actual schedules are evaluated from survey research such as Nielsen. Because reach is a factor of duplication, as a schedule grow in size, the reach added by each increment is less and less. When reach is graphed against an axis of GRP or insertions or dollars, an asymptotic "curve" like the one below, is drawn. The actual formula which descibes this graphic curve is what is in reach evaluation software. Typically it is a regression of the frequencies vs GRP levels, because frequency, too, is linear.

The Guru imagines you are thinking of TV reach, but could be referring to radio, magazines, or internet, etc. There are different "curves" for any given medium / daypart / demographic / mix situation. If you use Nielsen actual data, the "curves" are -- in effect -- continuously updated. If you use other media software like Telmar or its competitors, you need to ask your representative how recent their update of formulae is. Curves based on reach vs GRP are not very variable over time unless there is a major change in the medium.

For example, Telemundo's Hispanic TV reach system "STRETCH2," was updated in 1998 (by running new Nielsen actual schedules), 5 years after its introduction . There was no significant change in reaches.

But looking at general TV reach curves from the days before cable was significant, versus today's would show big differences.


Friday, January 12, 2001 #4096
How do I convert HH numbers into a Demo number. In some markets, my clients want me to post weekly to keep on top of shortfall, however, that's means using a HH number from the overnights. I need to see how that relates to the Demo. Can we just assign a HH and demo ranking going in and then check HH to HH - or can I use a formula to convert.

The Media Guru Answers(Saturday, January 13, 2001 ):
There is no formula that works in the absence of data such as viewers per viewing household or demo audience in thousands. Lacking those, the Guru would take the average ratio of HH to demo audience by daypart, according to the latest available demographic data. Use these ratios as a factor to apply to the HH overnights for your tracking.


Saturday, December 23, 2000 #4063
Dear Guru, I am a very new media planner so I have a very basic question. What is the difference between average Frequency and average OTS and what is the formula for their calculation. Thanking you in advace.

The Media Guru Answers(Saturday, December 23, 2000 ):
"OTS" or "opportunities to see" is used differently by various practitioners. One meaning is equivalent to impressions, or the number of exposures of a campaign to individual members ot the target demographic; a summing of the audiences of all the advertsing occasions of a campaign. In this sense, "average" is not an appropriate modifier.

Average frequency is the average number of exposures experienced by the members of the target who have been exposed to the campaign (net reach) over a measured time period such as 4 weeks.

formula:
Gross impressions ÷ net reach
or
GRPs ÷ percent reach.


Thursday, December 07, 2000 #4026
Dear Guru, If there are 2 different target groups need to be sufficient in one TV schedule, the weight of rating for Target A is 40%, for Target B is 60%. how to calculate/evaluate the performance? and does it have a standard formula? Thanks for your answer in advance. Sara Shiung

The Media Guru Answers(Friday, December 08, 2000 ):
If the Guru correctly understands your query, it seems like a simple weighted average would work.


Thursday, December 07, 2000 #4025
What is the formula for cost per thousand?

The Media Guru Answers(Thursday, December 07, 2000 ):
Cost ÷ impressions expressed in thousands.


Tuesday, December 05, 2000 #4016
Hollow, Dear Guru! Can You help me please to clearify, is it possible to predict sales if we know expected advertising campaign effectivness? I mean can we somehow correlate pre-campaign analysys data with data we get from the client about the product? Is there any formulas and methods and what information about advertised product do I need?

The Media Guru Answers(Wednesday, December 06, 2000 ):
A.C. Nielsens' BASES is a system for this sort of analysis.


Thursday, November 09, 2000 #3958
What is the definition of dispersion and what is the formula? We are looking at various demos, their indexes across two programs to find out how stongly the shows are affiliated demographicaly. Is it a valid method to achieve such an objective.

The Media Guru Answers(Sunday, November 12, 2000 ):
You haven't stated an objective. "Dispersion" refers to the degree of difference in media outlet selection in your schedule. In TV it ususally refers to the number of different programs, in radio to the number of different stations, but may mean different dayparts. The usual basis for specifiying dispersion is how the reach models were constructed.


Wednesday, November 08, 2000 #3950
Dear Guru, How is reach and frequency determined for a print (magazine) schedule?

The Media Guru Answers(Sunday, November 12, 2000 ):
The average issue audience, measured duplication between issues of the same publication and between different publications are compiled using various formulas. Generally commercial media software like Telmar's or that of the magazine measurement vendors is used.


Thursday, October 19, 2000 #3897
Dear Guru: My events department asked my how to estimate the "media value" of a product metion during the lead story of a primetime show like entertainment tonight. I told them that this was a very broad question, and it would vary depending on who the target was, what the ratings were, and what value really meant (i.e, dollars? contirbution to product sales? % contribution to frequency of a campaign, etc. They didn't know. Can you confirm how to go about this? What info do I really need? Am I on the right track? Do you have any math formulas to estimate this? Thanks!

The Media Guru Answers(Thursday, October 19, 2000 ):
Your thinking is exactly right. The Guru kows you as a regular and recognizes that you have followed his thinking from replies to past queries.

In terms of "media value" you would best stick to media metrics, like dollars, reach, frequency, etc. In considering dollars, you can relate the length of the metion --full context, not just brand name mention -- to price of commercials.

If thinking about impact, the Guru believes such a mention, is worth twice as much as advertising because of its implied indorsement. This of course assumes it's a positive mention, not something like "the strangler's weapon was a pair of Donna Karan pantyhose."


Wednesday, August 30, 2000 #3767
Dear Guru, we are getting into awareness based media planning which means objective will be set on awareness scores, rather than GRP, R&F. Please tell me the factors which are required and procedure for setting awareness objectives.Thank you

The Media Guru Answers(Friday, September 01, 2000 ):
Very theoretical. There is no specific rule of thumb equating awareness to GRP. There will be a big difference in saying the objective is to achieve 30% brand awareness versus increasing an existing awarness of 30% by 30 points.

You should think about:

  • What percent of "aware" persons will be purchasers?
  • What number of purchases is the pay-out level of your advertising?
  • How often does the aware person make a purchase decision?
  • Assuming awareness never exceeds reach, what reach must you acheive and what decay rate can your afford to maintain the awareness that will drive sales?

Frankly the Guru believes that saying "awareness based media planning" is just putting a marketing spin on the media plan. Ultimately a media plan sophisticated enought to have objectives almost invariably has some awareness objective mentioned. And ultimately, media must be bought in terms of GRP or impressions or insertions; the media vendors do not sell quantities of awareness. So either you have a formula which equates awareness numbers to media units or you do not. The Guru does not.


Friday, August 25, 2000 #3747
can you please explain various tools through which one can determine the efficieny of a TV plan

The Media Guru Answers(Monday, August 28, 2000 ):
"Efficiency" has a standard definition, so it is subject to arithmetic formulas rather than tools. Efficiency is defined as cost per unit of audience. "Audience" might be expressed as impressions or rating points.

So "efficiency" usually means, CPM (Cost per Thousand), which is the cost of a schedule or advertising unit ÷ the sum audiences of the ad units (in thousands) and CPP (Cost per Point) is the cost of a schedule or advertising units ÷ the sum of the ratingss of the ad units.


Wednesday, August 23, 2000 #3737
I am trying to figure out the wearout for print. My target is African Americans 12-24 and 18-49. All I have is the FY reach, freg and TRPs. What would be my next steps?

The Media Guru Answers(Monday, August 28, 2000 ):
There are no accepted standard formulas for wear-out. By the nature of print, which tends to yield high reach adn low frequency, there is generally less concern about wear-out than in broadcast.

Some of the broadcast rules-of-thumb for wear out include "over 20 frequency in the second highest quintile" or "2000 GRP.

Niether of these are likely to occur in print. Custom research may be the only real way to evaluate this. Start with Starch.


Monday, August 21, 2000 #3728
What is the formula to equate reach and frequency from an outdoor showing? i.e. a 25 showing has a reach of 76.8% and a frequency of8.2 (I pulled these numbers from your media glossary)

The Media Guru Answers(Monday, August 21, 2000 ):
"25 Showing" in out-of-home media indicates a buy with a daily effective circulation, or traffic count, or impressions, which equate to 25 GRP per day.

In considering a month's reach & frequency, it is common to adjust the weekend days' traffic down by about 50%. In a month, instead of 25 X 30 = 750 GRP, we credit about 630 GRP. This agrees with the arithmetic of 76.8 Reach and 8.2 Frequency.


Friday, August 18, 2000 #3718
I am new in the field of internet advertising sales, and I have never sold ads for the media before. Are there any web based pricing charts or formulas to use for calculating conversion rates, cpm, cpc and cpa?

The Media Guru Answers(Saturday, August 19, 2000 ):
Sample pricing and a cpm calculator can be found at Ad Resource.

"CP_" anything means "cost per" whatever. It's simply cost divided by thousands of ad impressions or clicks or anything.


Wednesday, July 26, 2000 #3654
Please provide formula to manually calculate Reach & Frequency for press. Thanks

The Media Guru Answers(Saturday, July 29, 2000 ):
This calculation is very complicated. If you don't have detailed tables of duplication factors between different publications and between various numbers of multiple issues of the same publication, only fairly crude formulae are available.

Click here to see past Guru responses about reach calculation formulae.


Thursday, July 13, 2000 #3618
On July 5 you responded to a question regarding the decline of brand awareness due to reduced advertising activity. You indicated that the "formula predicts that a brand running low GRPs per week loses awareness and a brand with no activity loses 5-10% of the previous week's awareness each week." I would love to pass this information along to some clients. Is there a source I can quote?

The Media Guru Answers(Thursday, July 13, 2000 ):
"5-10%" is a general summary of experience with various estimates the Guru has found over many years.

The Guru has been told that some people are quite comfortable citing the
"AMIC Media Guru, http://www.amic.com/guru/index.html"
as an information source.

It shouldn't need documentation to understand that awarenness will decline when there is no advertising. It also seems easy to assume that it will be like an inverse reach curve:
constantly approaching 0% in constantly decreasing increments.

No doubt many supporting studies are available through The Advertising Research Foundation InfoCenter. For details about the InfoCenter, call 212-751-5656, extension 230.


Wednesday, July 05, 2000 #3598
lets assume that a company has been running a branding and image campaign for 12 months at 800points a month. If the company goes completely dark for 6 months what are the expected effects on awareness and branding. The negative effects of going dark at then end of a branding campaign have been taught to me during several courses I cannot remember nor find a formula or case study which proves this point. Where can I go to find statistics or case studies to support your answer. Thank you again for you help.

The Media Guru Answers(Wednesday, July 05, 2000 ):
The Guru can consider this in terms of ad awareness, since brand awareness is subject to so many more outside factors.

Whatever the level of advertising, awareness can never be more than 100%. One very simple formula the Guru has seen predicts awareness as a high percentage the previous week's awareness plus a small percentage of the current week's GRPs.

As will be obvious, this formula predicts that a brand running low GRP per week loses awarness. A brand with no activity loses 5-10% of the previous week's awareness each week.

Of course this is all general. One classic case is the old Certs "two, two, two mints in one" copy which had good awareness as a "current commercial" ten years after it last aired.


Thursday, June 01, 2000 #3522
Dear Guru, I teach my university's ad media course. In an effort to make it as useful and "real world" as possible, I want to know what topics/ideas/concepts you feel are absolutely critical to include. Also, we do use software designed for the college classroom to simulate buys. I would rather use the actual software buys. Suggestions on "real world" software we could purchase to utilize instead? Thanks, AdMedia Prof

The Media Guru Answers(Thursday, June 01, 2000 ):
The Guru believes the most important concepts are
  • Turning marketing / advertising strategies into media objectives
  • Turning media objectives into media strategies and tactics
  • They ways in which different media can support different strategies
  • Basic media math and statistical definitions
. Of course, these are broad concepts which encompass a lot of detail. A person should come out of an advertising media cousre equipped, for example, to
  • recommend radio when it's more appropriate than TV
  • Demonstrate how internet advertising is often more sizzle than steak, but has its place in some plans.
  • Make media plans address the fact that the U.S. is presently about 30% African American, Hispanic or Asian American, that this proportion is growing rapidly and already 40-50% in the "major markets" that will come up on many brands' key market lists
.

Learning the audience data comes with the job and changes too fast for details learned in college to retain validity very long into real world jobs.

As for buying software Donovan Data Systems is the "mother of all" buying software.


Thursday, March 16, 2000 #3326
Dear Guru: I would like to know if there is any equation to calculate media mix reach?

The Media Guru Answers(Thursday, March 16, 2000 ):
There are several, equivalent ways to express the arithmetic to combines media according to random probability, which has been found generally adequate for the purpose of multimedia combination.

Here's an easy one:

  1. Work with two reaches at a time
  2. Treat the reach of each medium as a decimal (50 reach is 0.5)
  3. Add reach of medium A and medium B
  4. Multiply reach of medium A by Reach of medium B
  5. Subtract the product of the multiplication from the sum of the addition

Example:

  • Reach of medium A = 40, reach of medium B = 55
  • 0.4 + 0.55 = 0.95
  • 0.40 x 0.55 = 0.22
  • 0.95 - 0.22 = 0.73
  • Combined reach is 73

To add additional media, treat the combination as medium A and the next medium as B.

In some cases, a planner may have access to research which shows that an adjustment should be made for actual, measured, duplication between different media, rather than use the "random probability" formula above. In that case, more sophisticated reach calculating software packages, such as those from Telmar allow you to make the calculation and build in known adjustments.


Tuesday, March 07, 2000 #3291
Is there a formula which calculates effective reach and frequency? I know that reach x frequency=grp's, but how can I determine what the effective reach and frequency would be for 100 grp's or 150 grp's?

The Media Guru Answers(Friday, March 10, 2000 ):
Of course there's a formula, but it can be immensely complicated. In fact, media planners rarely, if ever, considered effective frequency before computers became a part of everyday reach and frequency calculation in the 70's.

Your "reach x frequency=grp's" is not a formula, but merely the arithmetical relationship of these quantities as they are defined.

GRPs are the convenient weights and mesures we use in media buying. They are simple statistical measurements, whereas reach and frequency are more complex statistical models In some cases, there are relatively simple reach formulae derived from compiling the actual, measured reaches of actual schedules with known GRPs. The formula is non-linear.

To find the effective reach of a schedule, you first determine level of frequency to consider "effective" and then examine the frequency distribution of the schedule to see how many people have been reached that number of times The frequency distribution shows exactly how many people have been exposed to each integral number of announcements in a schedule.

The math is based on non-linear functions. For any given reach and GRP set, the frequency distribution can vary considerably depending on the media combined and the dayparts within the media.


Thursday, March 02, 2000 #3274
What are the criteria that a media planner has to consider when planning for advertising on the internet?

The Media Guru Answers(Saturday, March 04, 2000 ):
The criteria are the same as in any media planning: reach, environment, composition, consumer response, etc.

In the internet there are merely different sources, standards, and formulas in dealing with these elements and thousands more options.

A couple of the most important differences are

  • One "page" of a web site gets only a fraction of the audience of the total site, as compared to a page of a magazine, which is treated as if it had the same audience as the entire issue
  • Audience ranking is much less relevant for the same reason: If Yahoo reaches half of all web users, but your banner is only exposed to one million of those unique visitors, how is that different than you banner being seen by one million uniques visitors to a web site which only gets one percent of all web users?


Wednesday, February 23, 2000 #3239
Dear Guru: I need to analyze a cpm tv negotiation on w1849. I would like to transfer the negotiated w1849 cpm to w2549. Can you please explain the formula to transfer Thanks.

The Media Guru Answers(Thursday, February 24, 2000 ):
Step 1: calculate the vph ratio (or impressions ratio) of w25-49 versus w18-49.
Step 2: divide the w18-49 cpm by this ratio.

Example:
Suppose w18-49 CPM = $10.00
Suppose the w18-49 vph is .700 and w25-49 is .600
then the ratio is
.600 ÷ .700 or
.857
Then $10.00 ÷ 0.857 = $11.66

It's best if you have the actual vph or impressions of your buy, but you can make an estimate from the daypart averages.


Thursday, January 20, 2000 #3136
Is there a simplified reach and frequency calculation formula that allows for the number of stations (TV or radio) as well as the target audience size?

The Media Guru Answers(Saturday, January 22, 2000 ):
Reach and frequency calculations have become quite complex today and are typically done by computer. Because reach is curvilinear, the formula can be quite complex, even without this issue. A different algorithm is needed for each dispersion scenario.

A good system will account for number of stations, at least in radio; AMIC's sister company, Telmar has such a system.

Since reach calculations are typically done with percentages of universe, like rating and percent reach, target audience size is not specifically relevant. Different curves will have been deduced for different targets, based on their accumulation patterns, which may not exhibit a direct correlataion to size. If reach in thousands is needed. it is simple to calculate by multiplying perent reach against target population.


Wednesday, January 05, 2000 #3096
Oh Great Guru -- I need to calculate GRPs, but I don't have reach or frequency on some tv buys. I do have CPM, total impressions and impressions/week and the total population of the demographic. Can you supply a formula for calculating GRP based on what I have?

The Media Guru Answers(Wednesday, January 05, 2000 ):
(Impressions divided by population) x 100 = GRP.

For example,
if impressions are 2 million and population is 1 million, GRPs = 200.


Monday, December 20, 1999 #3061
Dear Media Guru, we are currently in the process of conducting a dip stick media survey to be integrated in a media reviews presentation for an FMCG. Based on your experience and references what would be the minimum acceptable sample size to use in order to insure the research findings are viable and reliable ? Note that the total population in our market is close to eighteen million, and the specified target group is about ten million. Thanks.

The Media Guru Answers(Monday, December 20, 1999 ):
The population is not really relevant to determining the reliability of a sample.

The key consideration really is: what size are the answers you expect and what potential error can you stand in your decision making?

The formula to calculate one standard error (68% confidence) is:
The square root of ((P times Q)divided by N),
where

  • P is the percentage of the sample offering the response to test (treated as a decimal fraction)
  • Q is the remaining percentage of the sample, and
  • N is the sample size
For 90% confidence, the above formula is multiplied by 1.645.

When you hear that results of a political poll are +/- 3%, this is the range of error around a 50% answer, usually at "90% confidence," meaning that if the poll was repeated with the same sample size, 90 times out of 100 the same question would have a response between 47 and 53%.

"+/-3%" on an answer of 50% means 6% relative error.

A sample size of 750 would bring you +/- 3% on a 50% answer:

100% - 50% = 50%

P=0.50, Q=0.50 and N= 750

0.50 x 0.50 = 0.25

0.25 / 750 = 0.000333333

Square root of 0.000333333 = 1.8275

1.8275 x 1.645 = 3.003

That's fine for political polls, where responses tend to hover around 50%. But in media studies, 1% or 2% may be exposed to a given ad placement. The same 750 sample would give reliability of +/- 0.84 on a 2% response, which is a relative error of 42%.

So, use this formula with your anticipated answer sizes and the level of relative error with which you can comfortably make decisions to determine a suitable sample size.


Thursday, December 09, 1999 #3039
dear guru how can i estimate reach precentages? is their any model that i can study from? i ask you before about raech and you answered that its a judgement decision. i am trying to estimate how many people will wxposed once , twice, and more to my ads on t.v ( old brand, the first time to adverise , direct competitores are not using advertise at all the largest share of voice, the target audience: main shopper with children ) is it enough to compare my case to other t.v campaign which had some close goals( target, budgets, adverisment environment, and so on) or may you has any other way to guide me? please try to help me many thanks

The Media Guru Answers(Thursday, December 09, 1999 ):
There are many parameters to consider for various media and dayparts. Computer models seem to be the only sensible way to deal with all of today's options. AMIC's sister company, Telmar, which has offices in your country (Israel), is the leading worldwide provider of this type of software.

Statistical texts can give you information about some of the basic reach estimating formulas, such as the Beta Bi-modal function.


Tuesday, December 07, 1999 #3033
Without the budget for post-flight call out surveys what formulas or 'rules' can I use to anticipate message saturation and burn. What reach or net reach level over what period of time would be probable to achieve a 80% awareness within the target. Also what is considered too much exposure for one message before you reach a point of diminishing returns. I know that the the better measurment here is research before and during the campaign, but there must be some bench marks that are industry accepted. Can you share these and share a public location for other general assumptions like this. Thank you in advance Guru... J

The Media Guru Answers(Wednesday, December 08, 1999 ):
  1. Ad awareness will never be greater than reach, so start from a plan that delivers at least 80% reach
  2. To establish measurable awareness, some repetiton will be needed, so think about getting an 80% reach at a set effective frequency level. The Guru has previously discussed use of the Ostrow Model to set this goal.
  3. A message is worn out when its ability to generate sales falls off. This being hard to predict, many advertisers have used past experience to set media-measurement based cut-offs. These have included a limit of 2000 GRPs and a frequency cap of 20 in the second highest quintile. In reality, the size of the copy pool, the qualities of the copy, the target, the overall media mix, and product category may all lead to wide variations in wear out. The two standards mentioned above were both commonly used in basic package goods TV advertising in a mix with print and a TV copy pool of 2-3 executions.


Thursday, November 18, 1999 #2984
what advertising agents do,how they do it,modes of renumeration and types of advertising agencies

The Media Guru Answers(Sunday, November 28, 1999 ):
Most basically, advertising agencies create and place advertising in the media. Agencies also participate in and herlp guide marketing planning. The services are traditionally compensated by 15% commission on gross media bought and 17.65% on net production or other out of pocket expenditures - 15% of gross and 17.65% of net are actually identical proportions.

Some agencies specialize in product categories and others may specialize in specific consumer categories, like medical professionals. Other specialize in media like on-line.

Compensation deals are most likley to vary from the 15% formula for very large or very small accounts.


Friday, November 05, 1999 #2938
I'm hoping develop a reach curve for a client to shhow how audience accumuluates with increased dollar spending in the market. I have a table that shows % reached by GRPs per 4 weeks and wondered where I could get published tables and surveys realting to increased share of voice in realtion to share of market spending. Is there are projection formula that could be used?

The Media Guru Answers(Wednesday, November 10, 1999 ):
Share of voice usually means share of GRPs. Developing a Cost Per GRP index would give you a simple conversion. The shortcoming of share of voice is that it ignores impact differences between various media and copy units, unless comlex formulae to equate GRPs are created.


Tuesday, November 02, 1999 #2928
Guru: I'm trying to plan an online media buy for branding purposes and having a hard time devising a formula for adequate impressions levels. I think % reach is a better way to go, but what's the optimal % reach for online branding on a website (high enough frequency without waste)? Thanks!

The Media Guru Answers(Wednesday, November 03, 1999 ):
It is very early in the scheme of internet reach models to imagine that there are standardized formulas.

You are correct to think that "branding," which means different things to different people, but seems to be about awareness in most definitions, depends upon reach.

But reach in relation to internet impressions is a curious thing. As in all media, it depends upon duplication between one day's visitors and the next plus duplication between one site's visitors and another site's.

When reach formulas are created, they begin from examination of the actual reach and frequency in real advertisers' schedules.

In this connection, it is instructive to visit the "Top 10 Advertisers of the Month" page at Nielsen//Netratings, a web audience research firm. In the month of September, 1999, the #1 advertiser, in terms of impressions, was TRUSTe, with 945 million immpressions and 25% reach among persons with internet access. But Amazon.com, the advertiser with the highest reach, at 44%, had less than one-third as many impressions, 273 million. Other advertisers with as few as 103 million impressions surpassed TRUSTe's reach.

The bottom line is that

  • Clearly, there is not a lot of consumer reach possible on the web, if the top advertisers' perform like this.
  • Impressions-to-reach models are going to be complicated to build.
  • We probably need a new definition of "branding" for on-line purposes.


Saturday, October 30, 1999 #2921
Dear Guru. How do we compare national TV-sponsorship in terms of cpm, with traditional spot buying? In order to do this we need to evaluate the lenght, creative factor and the added value of presenting the program. I have used formulas including these factors using indeces. Is this the "right" way of doing it? Do you have these formulas, indeces?

The Media Guru Answers(Monday, November 01, 1999 ):
Most of the comparison should be purely and simply cost-based.

Length and creative would not be a part of the difference between national and spot. The same commercial can run in either environment.

If you literally mean national sponsorship, that is with Opening and/or Closing billboards, this can be quantified by added length. As for formulas and indices, if you get ten "free" seconds of airtime, it is worth one-third of what you paid for a thirty. Any other element of national vs local is purely a matter of price and geography. Allowing a value for "in-program" positions versus in-break would be a judgement call and not worth much, in the Guru's opinion.


Wednesday, October 20, 1999 #2892
Dear Guru, I am attempting to do a publicty report for the coverage (unpaid) our organization receives on a quarterly basis. I have been calculating the advertising value of publicity, based on what each medium would typically charge for that size ad. However, I am looking for a formula to calculate the publicity value of such coverage. I understand that the National PRSA has come up with a formula to calculate this (something like X 3 for television and X 6 for print), but I haven't been able to substantiate this. Can you help?

The Media Guru Answers(Wednesday, October 20, 1999 ):
The Guru doesn't deal with publicity, but if PRSA has a standard, the advantage is that it is a standard.


Thursday, September 30, 1999 #2838
Useing TV's formula for ratings, apply to the newspapers circulation of 108,000 with a population of adults 289,400. What would be a rating number for this situation?

The Media Guru Answers(Friday, October 01, 1999 ):
If we know that the circulation is 108,000, we next need to consider the readers-per-copy to get your answer. According to the The Newspaper Advertising Association the 1999 daily newspaper's average adult readers-per-copy is 2.148. Therefore, your 108,000 circulation would have 108,000 x 2.148 or 231,984 readers.

With an adult population of 289,400, the rating would be 231,984 ÷ 289,400 or 80.2, which indicates a very popular newspaper, indded.


Monday, September 27, 1999 #2830
I have read all your responses regarding recency. If you wouldn’t mind answering a few more, this is a multiple question predominantly regarding recency as a planning theory. 1) What Telemar program deals with TV R&F on a weekly basis? 2) Do the same audience accumulation formulas work for a one-week cume vs. 4wk or 52 wk? 3) When now planning an a weekly basis rather than a flighted basis are frequency guidelines or goals a consideration in the recency planning theory? 4) Has there been a clear industry swing relative to EF or recency yet? 5) A 1997 JAR article by Erwin Ephron cited some minimum target reach guidelines like 35 weekly, 65 four-week and 80 quarterly. Has there been anything more definitively determined since then (I noticed reply 2631 7/14/99 lowering the weekly reach to 30)? 6) For those espousing recency, is the trend to a 52 presence or extended flighting like 8-10 continuous weeks of each quarter? 7) On the Effective Frequency side, where the defacto goal has centered around the 3+ level, has the time frame shifted to anything other than a 4-week period?

The Media Guru Answers(Wednesday, September 29, 1999 ):
1) Media Maestro and TV Buyer handle TV R&F.

2) No, formulas differ for one week, 4 week, and long term. 400 GRP, spread ove differend programs might come close to exhausting the reach potential of one week's TV audience, but not if spread over 4 weeks or longer.

3) Recency planning is focused on weekly reach, and incorporates the concept that every exposure after the third one is at the 3+ level.

4) Some have adopted recency, some cling to effective reach. The Guru is not aware of any polls of agencies or advertisers, but suspects that recency is still growing in acceptance, but is a minority approach.

5) The reach minima are a bit loose, and 30 vs 35 is not a major point of contention.

6) The idea of recency is that being there whenever a purchase decision is made is ideal. Flighting, when continuity is affordable and there is no major seasonality is contrary to the principle.

7) Four weeks has always been somewhat arbitrary, likley stemming from the one-time dominance of monthly magazines. But it is a convenient benchmark. A logical approach can set a level other than 3+ or other than 4 weeks, etc.


Wednesday, September 22, 1999 #2815
Can you please refresh my memory and tell me how to calculate multi-week reach and frequency across television and radio? Thank you

The Media Guru Answers(Thursday, September 23, 1999 ):
If you mean combining these media, the formula has been addressed. Click here to see past Guru responses.

If you mean how to get multiweek reaches for either medium, you need reach curves or software, the extension formulae are tow complex for casual use.


Tuesday, September 14, 1999 #2795
Dear Guru, I am writing to you from the Middle East. First of all I am very excited to discover the AMIC site. I have recently been exposed to various documentation on the recency theory. Alongwith the documentation I have seen something called reach curves. The reach curves I have seen are typically for 1+, 2+, and 3+ levels for all adults and all women audiences. I understand it is an easy way to translate Effective Reach goals into GRP goals e.g. X GRPs will get you Y% 3+ reach against the target. It also clearly depicts the point of diminishing return. I am eager to know how I can develop reach curves for my market. Can this be done by us in the media department or do we need to approach some company which specializes in this area. What sort of data is required? Just to give you a background, we are not a metered market. TV audience measurement is conducted thrice a year using face-to-face interviews with a representative sample. Viewership is typically available by 15 minute time segments for all channels across various demos. Thanks in advance.

The Media Guru Answers(Tuesday, September 14, 1999 ):
Reach curves have been in use since long before computers were used in media departments and long before metered measurement.

Curves are created by using the reach of actual schedules. For example, in the U.S., Nielsen would report the actual reach of specific brands' schedules, based on examining the net unduplicated viewers in their reasearch data who viewed the program schedules used by the brand's commercials.

Once you have several schedules ( 8 or so will do) with actual reaches and frequencies for various GRP levels, you can use the regression analysis data function in a spreadsheet, like MS Excel or Lotus 1-2-3, to calculate a formula which describes the curve. This formula can literally draw the curve on a graph, or let you build a table of GRP / Reach pairs. By the way, it is the frequency and GRPs which are used in building this regression, because while reach is a curve, frequency is a straight line.


Tuesday, September 14, 1999 #2792
What can you tell me about reach-based planning? Thank you in advance.

The Media Guru Answers(Tuesday, September 14, 1999 ):
> The usual assumption is that print and broadcast duplicate with random probability, there is no special, greater or lesser likelihood that persons in the audience of the print schedule will also be or not be in the audience of the broadcast schedule.

Mechanically. the combination may be calculated in a few equivalent ways. The Guru finds it easiest to consider the reaches as decimals (50% reach = 0.50).

Subtract the reach of print from 1 and multiply this by 1minus the reach of broadcast. Suppose print has a 40% reach and broadcast has 55%.

By subtracting 0.4 from 1 (1 - 0.4 = 0.6), you have the probabilty of the target not being exposed to print. Subtract 0.55 from 1 to get the probability of not being exposed to broadcast (1 - 0.55 = 0.45)

Multiply these two together (0.6 * 0.45 = 0.27) and you have determined there is a 27% probability of people not being exposed to either of the combined media, or a 73% reach.

This formula is typically used in media software to combine different media.

Certainly there are cases where there is a somewhat better than random probabilty of media duplication, such as TV Guide combining with a TV schedule, but that's the exception, calling for judgement.


Wednesday, September 01, 1999 #2759
Is the random probability formula used to combine reach for different media also valid when looking at effective reach (i.e. 4+ level)?

The Media Guru Answers(Thursday, September 02, 1999 ):
If you mean, can you combine the 4+ reach of one medium with the 4+ reach of another medium to get the 4+ reach of the two combined media, the answer is no.

Among those who were reached 2 or 3 times by each medium, some will now be reached 4 or more times and some will not, yet these people are not considered by combining only the two four+ groups. There are also those reached only once by the first medium and three times by the other, etc. A new, overall calculation of the frequency distribution must be done, to determine the 4+ of the combination.


Thursday, August 19, 1999 #2729
Dear Guru, 1- Please let me know SQARE model that SQAD use to calculate CPP for TV and Radio. Please let me know the detail or any link I can find more information or books... 2- Do you know any model for reach vs GRPs? Our client ask us to show the data like that. The problem that we try to find the suitable daypart mix, station mix, medium mix that is good for our advertising strategy but we don't have any optimiser programs. We have only ratings data like Telescope and Prinscope of ACNielsen. Do you know any example to solve this kind of problem? 3- Our client also want to have a model to set advertising budget to get for example 80+ reach but we can not know until it happen. How to solve this issue? warmest regards, Thai Vang

The Media Guru Answers(Thursday, August 19, 1999 ):
A general explanation of SQAD's model is available from SQAD. They will give you the same information they would give the Guru. But the essence is manipulating actual buying data in real situations, provided confidentially by actual media buyers.

GRP's and reach do not have any standard realtionship, except within given media and population parameters. You are writing from Viet Nam, where Televison audience cume patterns are likely to be quite different than in the U.S. Even within the U.S., Hispanic TV reach curves are very, very differerent than the General Market TV reach curves.

The way to build a model, to oversimplify, is to collect a great number of actual reaches of real schedules, and then plot their frequency against reach in a regresssion analysis, which gives you the formula for the "curve." Frequency is plotted, rather than reach, because frequency is a straight line while reach is a curve. The curve formula then allows you to create a model with a reach solution for any GRP input. The more variables you use to build different curves, the more sophisticated your model can be.


Thursday, August 19, 1999 #2727
The formula for calculating the reach of media vehicles is (a+b)-a*b. Please tell me the "N" formula for it, or you have a different formula for calculating reach?

The Media Guru Answers(Saturday, August 21, 1999 ):
Your formula is for " random probabilty," which is used to combine two different media, based on the assumption that their audience duplication is purely at random. This formula is not appropriate to combining different vehicles in the same medium, which typically have more than merely random duplication.

There are various, quite complex formulae for computing reach of various vehicles of the same medium, among them the Beta Binomial, Lamda function, and others. The Guru is not familiar with your reference to "the 'N' formula."


Tuesday, July 20, 1999 #2649
Dear Guru, Could you please explain the formula for calculating median age for a TV Network based on AA(000). Also would looking at the Median age based on Reach(000), make sense. Thanks,

The Media Guru Answers(Friday, July 23, 1999 ):
The median of anything is the number that falls in the middle when everything is arranged in order. So to find median age, ideally you need to find out how many viewers are two years old, how many are three, etc up to 99+. If you can't get it by single year, get the smallest brackets possible. Then you find the age which has an equal number of people older than that agaand an equal number younger, this is the median age. If you are working with age goups instead of single years, you may have to assume that the median is the mid-point of the median age group, weighted according to the number older and younger.

For example, suppose there are 10 million viewers, and there are:
2 million age 2-11 years
2 million 12-17
3 million 18-24
1 million 25-34
1 million 35-49
and
1 million 50+.

With 10 million viewers you need to find the person who has 5 million people older than he or she in the audience and 5 million younger.

This person must be somewhere in the 18-24 group, because we can tell there are 4 million younger than this group and 3 million older.

Rather than just pick the mid-point of 18-24, you should interpolate according to the other numbers: the mid-point age should be 4/7 along the span 18-24, toward the younger end, or 20 years old.

What would the median age of the reach do for you? It's dependent on the viewing frequency of the network which may not correspond to the ad placements of your schedule.


Friday, July 16, 1999 #2641
Here's a basic math question for you: I recently bought a media (TV) schedule that gave me a total A18-49 delivery (in 000's) of 45000, 89 spots, total cost = $1,300,000. Knowing that the total A18-49 universe is 61350 (000), how do I find the following?: 1) total GRPs delivered 2) total CPP

The Media Guru Answers(Friday, July 16, 1999 ):
The GRP equation is 45,000,000 impressions divided by 61,350,000 universe, expressed as a percent, or 73 GRPs.

The CPP equation is $1,300,000 cost divided by 73 GRPs or $17,808 CPP

Guessing this is national cable, it seems high. to the Guru.


Monday, July 12, 1999 #2623
Reciently I have read a couple of documents that explain that you may estimate wearout using an equation(applying quintyl analysis). I would like to know if there is any equation to estimate hoe many grp's per version you need to generate awareness. As always thansk in advance.

The Media Guru Answers(Monday, July 12, 1999 ):
Any number of GRPs generate some awareness. So the question is how much aweareness do you want to achieve. Reach may tie more closely to awareness generation, but GRPs are easier to work with.

Also, consider whether you really care about awarness of individual commercial versions as opposed to advertising overall.

formulas the Guru has seen generally assume some beginning level of awareness and a fall-off in any week with less than100 GRP.


Monday, May 10, 1999 #2496
what are the various terminology used in electronic media & their various formulas?

The Media Guru Answers(Monday, May 10, 1999 ):
There are far too many terms to decribe here. See the Media Guru's Encyclopedia of Media Terms.

formulas for most have been provided in Guru answers from time to time. When you find one for which you need the formula, go to the Guru Archives Search Engine. Use the media term plus the word "formula" as your search terms.


Friday, April 30, 1999 #2481
Is there any way to calculate duplication across a media plan using several media (e.g. print and radio and TV), or can I only get a duplication analysis within a media (radio duplicaton and then another duplication factor for print, etc , etc) I use telmar for research with simmons and arbitron access and we also use JDS for buys.

The Media Guru Answers(Friday, April 30, 1999 ):
The standard assumption in media planning is that duplication between different media is purely at random. Therefore, the random probability formula is used:
  • Express the reach of each medium as a decimal (50% reach = 0.5)
  • Multiply the reach of one medium by another to determine the duplication.
  • Subtract the duplication from the sum of the two reaches to get the net reach

So, if you have a 40% reach in TV and a 55% reach in Print, multiply
0.4 x 0.55 to get 0.22
subtract 0.22 from 0.4+.55 and get 0.73 or
73% reach of the combined media.

There are a variety of ways to do the calculation. The Guru actually prefers to use the probablilty of not seeing each medium (reach as a decimal subtracted from 1.0) When these are multiplied they give the net probability of not seeing any of the media. When this result is subtracted from 1, the final result is net reach. This style is particulary useful for combining several media at once.The example would combine this way:

  • 1-0.4 = 0.6
  • 1-0.55 = 0.45
  • 0.6 x 0.45 = 0.27
  • 1-0.27 = 0.73 or

    73% reach.

Telmar's "Media Mix" program uses these assumptions.


Tuesday, March 30, 1999 #2421
The need: I am looking for a way to factor 'page exposure' data into mainstream media metrics such as CPM or GRP. MRI tracks and calculates page exposure using the following: (#_of_days_magazine_is_read * #_issues_read * %_of_pages_read)= avg_page_exposure I believe such data would not only provide a more accurate picture of a readers exposure to the ad pages but could alter CPM & GRP rates. My Reasoning: CPM=(ad_rate/audience); audience=(circ * readers); 'readers' is thenumber of different set of eyes per issue (single exposure). This number does not take into account how long or to what extent the reader looked at the publication -- it could be the mailman delivering the magazine who remebers the cover or it could denote a subscriber who reads the issue cover to cover. Enter the issue of page exposure. Suppose I am considering a magazine with a CPM of .01851 = 40,400/(704,000 * 3.1). However, if this same magazine provided me with a page exposure rate of .99 = (3 * 1 * .33) -- which says that the audience takes 3 days to read the issue and reads about 33% of the issue a day (which I know is unrealistic, but hear me out). Now suppose I take the .99 exposure rate and add it to the 'reader' and recalculate CPM --- 40,400/(704,000 * (3.1 +.99))= .01404 -- I get a much lower CPM. My Question: Why can't I make this type of calculation with page exposure data -- where is the break down in my logic or math? Any insights would be GREATLY appreciated. Thanks in advance!

The Media Guru Answers(Thursday, April 01, 1999 ):
First, overall, yes it is a reasonable and not unusual concept to adjust CPM according to additional measured factors reported for magazines. However, there are some minor and some major issues with your process in terms of labels and decimal places, etc.

Yes, CPM is ad rate ÷ readers. Readers is circulation times readers per copy (refer to the explanation of MRI information which the Guru did for you in query #2403).

So the basic CPM -- cost per thousand impressions -- in your example is actually $18.51, assuming you mean $40,400 is your ad csot, 704,000 is circulation and 3.1 is readers per copy.

The exposure rate is a factor, not an add on. So the adjustment would be 3.1 times 0.99 or 3.069 or virtually no change. The cpm is now $18.70. If there was a very different page exposure factor it would make a difference. It is a valid way to reaxamine CPMs.


Tuesday, March 23, 1999 #2403
I have been researching these questions for a number of days now and have been unsatisfied with the answers I have been receiving. I am a new member and new to this field, any direction would be most helpful. Thank you in advance... 1) What is the difference between Rate Base (a number guaranteed by publishers and audited by ABC) and Readership (a number provided by, say, MRI) levels for magazine publications? 2) Which number (above) is most often used to calculate CPM (I believe this calculation is ad_page_rate/readership)? 3) Is 'readership' really a composite number (perhaps a result of some other formula)? If so, does Page Exposure Rates factor into 'readership'?

The Media Guru Answers(Tuesday, March 23, 1999 ):
If you went to AMIC's Rates, Dates and Data area and clicked the link
"Audience data from MRI is available for
Fall 1998 for Total Audience, Circulation and Readers Per Copy
" you would see the table from which this image is taken:



The following discussion will use this table as a visual aid.

"Rate base" refers to circulation, the actual number of copies of a publication printed and sold for the average issue over a specified period of time. In the table, "Circulation" is the middle column of data.

"Readership" is the number of readers of the average issue. It includes "passalong" readers, who may not be the buyers / subscribers but read some else's copy. In almost every case, total readership will be greater than circulation. The first three columns of the MRI table we are looking at are readership numbers.

CPM can be calculated based on either circulation or readership. The circulation CPM (Cost Per Thousand) calculation is: divide ad cost by the number of copies in circulation.

The readership cpm calculation is: Divide ad cost by number of readers of an average issue. Often readers within a specified demographic the advertiser is targeting are the divisor in this second calculation. As a planning tool, the readership CPM is more common than the circulation CPM, especially for categories of print that use readership research, such as MRI.

Many people misinterpret the common reporting of "readers per copy." The last three columns of the MRI data are readers per copy figures. What audience research actually measures is readership. A random sample of consumers is interviewed and asked about their magazine reading to determine how many readers there are for an average issue of a magazine. Readers per copy is a calculation done after the fact, dividing the readers measured by the circulation. It is a handy factor used to compare magazine pass-alongs or to calculate other audience elements.


Friday, March 19, 1999 #2400
I need to know the calculation to work out margin of error for TV reach and frequency results. E.g. what is the margin of error of 40% @ 2+ depending on the size of the sample, penetration etc.

The Media Guru Answers(Saturday, March 20, 1999 ):
Assuming you are using a model to calculate reach and frequency, your error is no longer an aspect of sample size but of the reliability of the model.

For instance, suppose your schedule consisted of 20 advertisements with an average rating of 10. And, based on sample size, the 10 rating was +/- 2 rating points (or 20% relative error). But your total schedule of 200 GRP is not going to be +/- 40 points. Because error is plus or minus, there is an equal chance that one 10 rating is really PLUS 2 and the next 10 rating is really MINUS 2. So, in a schedule, most of the error cancels out. This is one reason why ratings minima for buying are often short-sighted.

When it comes to reach analysis, someone might have built a model by compiling several actual schedules measured by the original research and finding a formula for the straight line formed by the average frequency of each. Since the actual schedules came from the orignal research, the sampling error of each (minimized by the plus or minus aspect of the schedule elements, as above) could have been calculated. But now the "curve" coming out of the model is only judged by its ability to match back to actual schedules.


Thursday, March 11, 1999 #2384
Dear Media Guru Suddenly without my Strata software...what was the formula I learned so long ago for calculating Gross Rating Points?

The Media Guru Answers(Friday, March 12, 1999 ):
The Guru has discussed this frequently.
Click here to see past Guru responses on GRP and calculations.


Wednesday, March 10, 1999 #2382
RE: My earlier question #2379, my boss responded this way: Pre-launch was a 2-week period, so an average 4-week number would have been a misrepresentation of reality. If you do not have a 4-wk period for comparison than you should not do a 4-week r/f. Do you agree with this? How should I handle this disagreement with my supervisor?

The Media Guru Answers(Wednesday, March 10, 1999 ):
The Guru disagrees. The phrase "average four week" in the context of Reach & Frequency refers to a rate of accumulation, not really the period of time other than the time periods actually measured in the original establishment of reach calculations. Four weeks was originally chosen as the basis for the actual measurements that built the formulae when monthly media (magazines) were the predominant national advertising media. One does not really care how much time is involved.

For marketing purposes, what is important is that you communicated an advertising message to X% of consumers an average of Y times. It is easy enough to say that "over two weeks, we reached 60% of the target an average of 3.9 times." No one is misled, nothing is invalid. You just happened to use a four week formula to determine the results. As the Guru said earlier. only in some 1-week cases will there be any real differerence. (As there would for long term cumes, like 13 week).

If your supervisor's only alternative is to report nothing, as if there was no way to measure the schedule, that doesn't seem productive.


Monday, March 08, 1999 #2378
How do you figure out average four week r/fs without software? Thanks for your help.

The Media Guru Answers(Monday, March 08, 1999 ):
Before software, there were tables to get reach from broadcast GRP, and books of factors and formulae for print.

Those old tables are probably no longer valid, perhaps someone has done some new ones. The Guru has discussed this frequently.
Click here to see past Guru responses on reach and frequency


Monday, March 01, 1999 #2363
Dear Guru, We found a formula that is supposed to calculate newspaper impressions. (insertion X circulation*2.28*0.58)/1000) We thought that this was calculated simply by multiplying the circ by the # of insertions. Do you know what this formula could be doing? Thanks

The Media Guru Answers(Monday, March 01, 1999 ):
The Guru believes this formula is meant to estimate persons impressions. "Circulation" represents just copies, not readers.

The 2.28 factor looks like the Sunday average adult readers per copy. The 0.58 then would seem to be the composition for some demographic group, perhaps 18-49. The "/1000" seem to be meant to set the decimal for the particular context in which you found the formula, it will cause the result to be expressed in thousands. Perhaps the number of impressions derived from this formula was going to be used to calculate cpm.

See The Newspaper Advertising Association research databank. for other readers-per-copy and demographic composition data


Tuesday, February 02, 1999 #2303
I am working on a BPA/ABC circ analysis for 2 trade publications. One is BPA audited and the other ABC audited. On an apples to apples basis, how would I go about calculating a renewal analysis of average qualified subs for the BPA audited pub? I.E. The ABC audited pub calculates the renewal rate accordingly: Total Qualified Circ 1000 One Yr Total Subs Deleted* 200 Annual % not Renewed 200/1000 = 20% Annual % Renewed 800/1000 = 80% *Can this formula be applied to calculate renewal % for a BPA audited pub? I question whether we can integrate the "one year total subs deleted" figure as part of the equation. Thank you.

The Media Guru Answers(Thursday, February 04, 1999 ):
If the same data is reported on the same basis, comparison is fair. If comparable data is not reported, perhaps this is not a crucial analysis. The Guru believes this sort of analysis is likley to be a last-chance tie-breaker at best.


Tuesday, January 26, 1999 #2289
Is there a formula that radio stations use to determine the rate an advertising agency or buying service must pay for advertising? Also, would you know what the Total HH Universe for Radio in America is , or where can I find this information?

The Media Guru Answers(Tuesday, January 26, 1999 ):
In setting rates, of course a station must cover its costs of operation. But radio is a negotiable medium and the station has to consider what the marketplace pricing (cost per point) is for the demographics in which they have strength or wish to sell.

The U.S. Household universe for radio is the total household universe, or roughly 100 million. But, because radio is a highly personal medium, and audiences are based on individual listening, households are not considered relevant for radio. Radio ratings for households haven't been provided in standard research for 30 years or more.


Tuesday, January 19, 1999 #2276
What you can tell me about GRP and CPT? How to explain the formulas of them?

The Media Guru Answers(Tuesday, January 19, 1999 ):
The Guru assumes that by CPT, you mean "Cost per Thousand," which is abbreviated "CPM" in the U.S., (using the Roman numeral "M" for one thousand)>

GRP stands for "Gross Rating Points." It is the sum of all the ratings of all the advertisements of a schedule. Or it is the sum of all the impressions of a schedule divided by the population of the geographic market under consideration. "Impressions" and "Population" must be in the same demographic category within the same geography when applying this formula.

CPT, or cost per thousand, is simple a matter of dividing the cost of media by the number of impressions delivered expressed in thousands.


Tuesday, December 22, 1998 #2232
We use a buying service for our media. I'm just learning and was asked what seems a simple question, but do I have all the elements and could you help me to formulate the equation to learn. We are running 125 TRP's weekly in radio flighted thoughout the year. 3,000 total TRP's for the year. $550,000 total budget. CPP ranges from $32 to $200, average is $90. Q. With 125 TRP's a week, approximately how many spots a week will this schedule produce?

The Media Guru Answers(Wednesday, December 23, 1998 ):
The Guru assumes you are running 125 GRP in each market.

Depending on market and demographic, average ratings run from about 1.0 - 2.0 on top stations. Divide GRP by the average rating you will buy to estimate number of spots. At an average rating of 1.0, 125 GRPs represents 125 spots.

And you didn't need any of that cost or cpp data.


Monday, December 21, 1998 #2230
I am currently analyzing a media schedule that includes consumer print, trade print and national cable. I have been asked to pull a reach and frequency for the entire schedule. I realize that I am working with several differenct universes. I have added the circulations and pulled the gross impressions for cable. I have added those together. Is there any formular to determan a reach and frequency? Help?

The Media Guru Answers(Thursday, December 24, 1998 ):
In general, different media have different audience accumulation patterns when thinking about net unduplicated audience vs gross audience.

Calculating reach from a total multimedia impressions number is not practical unless the gross rating points (impressions divided by GRPs) is so many thousands that a 95+ reach can be assumed.

Some media, in particular broadcast media, allow general estimation of reach from a table of GRP levels. Print media are more complicated.

What you really need is standardized media software for reach and frequency calculation like that which is offered by AMIC 's sister company, Telmar.


Wednesday, December 02, 1998 #2193
Dear Guru! We were asked to prepare a presentation for one of our clients about media planning, since he works with several agencies and wants to concentrate the media planning in one of the agencies' hands. I visited the "parts of a Media Plan" which I found very helpful. Do you have some other tips? Specifically, we were asked to present a formula for a benchmark acocrding to we recommend to define what reach is needed for a campaign. Basically, we define it according to various factors such as competitors' share of voice, share of market goals etc. but we don't know any formula. We should be grateful if you supply any guidelined in this matter.

The Media Guru Answers(Wednesday, December 02, 1998 ):
You just need to formularize the thinking you are already doing.

For example, you could say that your formula to set reach for a campaign to equal competitor's share is:

Competitor's Reach times an index calculated by comparing the goal share to your current share. (i.e. to increase share 25%, exceed competitor's reach by 25%).

The Guru is not recommneding this particular formula, just illustrating how to turn philosophy into something apparently quantifiable.

Another approach is to build a matrix of your factors and set a 5 point scale for each; for example competitor's share: 0 point if it's equal to yours 1 point if it's 10% better, 5 points if it's 50% better, etc. Suppose you have 8 factors based on the sort of considerations you mentioned. Suppose further that you set a minumum for all campaigns of 50 reach (reaching the majority of the target). Now add a reach point for every point in the matrix. You have a maximum of 40 added points (90 reach), and an apparently highly logical "formula" for getting there.

The cleverness will be in setting up each 5 point scale. Or perhaps youy will have fewer factore and more possible point on each scale.


Monday, November 30, 1998 #2179
How do you manually work out reach and frequency for TV campaigns. Is there a particular formula?

The Media Guru Answers(Monday, November 30, 1998 ):
See the query of Tuesday, November 10, 1998 #2144. It is not feasible to do manual calcuations without tables, which are probably not being created any longer. Someone with the computer reach and frequency tool could develop the tables easily, but there would be little point.

Once reach has been determined for a range of possible schedules by various available means, there would be a fairly simple algebraic formula that describes the "curve." But, today, that's the long way around.


Thursday, October 22, 1998 #2107
WHAT IS CHANNEL BUNDLING? ON WHAT PRINCIPLES IS IT BASED & UNDER WHAT CIRCUMSTANCES IS IT FEASABLE TO TO formulaTE THIS STRATEGY?

The Media Guru Answers(Friday, October 23, 1998 ):
First, please do not send queries in all-upper-case.

Second, in regard to channel bundling, the Guru doesn't recognize this as a standard term. It may refer to buying/selling several cable networks under one ownership or representation.

Since cable ratings of individual channels are typically low, channel bundling can give a semblance of a bigger medium. As an nattempt at old-fashioned "roadblocking" it will fall short.


Thursday, September 17, 1998 #2047
what is crr?

The Media Guru Answers(Thursday, September 17, 1998 ):
The Guru is not familiar with this term. At a guess, it refers to cost per _____ rating. It may be a non-U.S. term the Guru has not encountered or it may be one companies own invented term from a system or formula of their own invention, similar to "persuasion rating point," which is discussed below.


Tuesday, September 08, 1998 #2031
Dear Guru, I'm new in the Advertising field. I would like to know how to calculate the Target Market Reach1+, Reach2+, abd the Average Frequency. TIA. -- SKY

The Media Guru Answers(Wednesday, September 09, 1998 ):
The answer depends upon what data you are starting with. At its most simple, "1+" reach is the same as just saying "reach". If you know the GRPs, and the reach, then the average frequency is calculated by dividing reach into GRPs.

At bottom however, in each medium, TV, radio, print, etc. reach was actually measured at some point, rather than calculated . That is, using respondent level measurement, such as Nielsen or MRI or Simmons, actual schedules advertiser were evaluated for gross audience accumulated and the net reach accumulated, as well as how many people saw exactly one advertisement in the schedule, how many saw 2, how many saw three, and so on. As the Guru stated above, reach is defined as those who saw one or more (1+) advertisements. 2+ or 3+, etc, is determined by adding those exposed to each discreet number of ads.

Taking the results of many of these schedules as a scatter graph, a classic reach curve may be plotted. Or, by arraying GRPs and frequencies in a table, a formula equivalent to the curve can be determined statistically. This formula then becomes a "model" for calculating reaches of other schedules in similar media. formulae for 2+, 3+ frequencies can also be calculated. There are no simple formulas for doing this. "Beta Bimodal" is one statistical function frquently used. These functions and models are usually built into large computer media planning systems like Telmar's.


Friday, September 04, 1998 #2028
I am currently pulling together information for one of my clients on national cable advertising. I have spoken with different network reps and have been told that they can not provide reach, frequency, or TRP's. They have said that they are not measured this way. Is this true? The network reps have provided gross impressions (in thousands). Is there a minimum threshold for this measurement?

The Media Guru Answers(Saturday, September 05, 1998 ):
Everything which has its impressions measured in national tv has TRPs, which is merely a calculation: the division of impressions by the relevant population base, either in the cable network's coverage area or the total U.S.

Any metered measurement can produce the data for calculation of reach of schedules or the production of formulae which will allow estimation of reach.

The Guru would guess you are dealing with smaller networks whose ratings and reach would be unimpressive and therefore are not a part of the sales effort.

A 0.1 rating is the usual threshold for reporting in a printed report. There may be a requirement to earn this rating over a specified time span before even this level is reported. On the other hand, networks with ratings normally below this level are likely to be bought strictly for their content/environment, not their audience delivery.


Friday, August 21, 1998 #2009
I'm having a difficult time trying to find any material that will teach me how to use CPP when buying network and spot radio. My contacts in the advertsing field tell me that they learned how to use this formula through experience. I know the formula for CPP. However, is there any resource that will show me how to implement CPP when buying network and spot radio? Something that will show me some shortcuts or maybe some examples? Thanks again for your help.

The Media Guru Answers(Friday, August 21, 1998 ):
Once you know how to calculate CPP, its uses are pretty straightforward.
  • CPP is an efficiency indicator. Media proposals you are considering can be ranked from lowest CPP to highest if efficency is a goal
  • CPP can be a goal you give to sales people, e.g. "I'm buying a $100 Women 18-49 CPP, what avails do you have at that pricing?"
  • CPP can be weighted with other factors like rating size or cume
  • CPP can be used to caluculate cpm when the universe is known: CPP divided by 1% of the universe expressed in thousands yields cpm
    (this is only valid when rating and audience in thousands come from the same geography as they do in Network. In spot, where you may use a metro rating but TSA thousands , the formula is imprecise at best)
  • CPP can be used as a bottom line number to compare possible schedules you are putting together

Remember - never average CPPs themselves; total the costs and total the ratings of schedules and calculate the bottom line CPP from the totals.


Friday, August 07, 1998 #1995
Hi media GURU, I have a question for you: What is the best way to evaluate an sponsorhip activity against a normal 30 second commercial? For sponsorship I mean, billboard on the stadium and/or on screen advertising during the games (sport), etc. Thank you for your advice.

The Media Guru Answers(Saturday, August 08, 1998 ):
The simplest comparison is time and audience. If your :30 commercial reaches 1 million people for :30 seconds and a stadium sign reaches an average of (for example) 20,000 people for an average of 90 minutes for 100 games. . . well, "you do the math."

In addition there's the chance of tv exposure of a stadium sign, which can be factored in the same way.

The premium value of sponsorship involvement with the team and sport is a judgement call.


Friday, July 31, 1998 #1981
Is there a formula that would indicate increases in effectiveness if a direct mail campaign is supported by other media? Example: TV and radio campaign to increase awareness of a product followed by a targeted mailing with a call to action. Thanks, Guru

The Media Guru Answers(Friday, July 31, 1998 ):
The Direct Marketing Association (DMA) would be the best source for such information.


Friday, July 24, 1998 #1973
I need help! I need to know the forumla (or formulas) for figuring the reach and frequency on a television schedule. I need it to be demo / and have the following information: universe, impressions and grps. What else do I need and what is the magic FORUMLA! At this point we are using the cumulative impressions into the universe to figure the reach - but could that be right? I don't think so - but the reach is what I need to figure (already have grp and freq is easy if I have reach!). Please help - and thanks tons.

The Media Guru Answers(Friday, July 24, 1998 ):
When you divide the accumulated impressions by the universe, your result is GRPs. There is no simple reach formula unless you already know GRPs and frequency. There are various very complicated algorithms for calculating reach for a given average rating size, known average duplication between programs used, etc. "Beta Bimodal" is one of the best known.

But today, Reach calculations are done by computer, using models built from Nielsen's actual measurements of net audience reach from meter-measured schedules.

Telmar, AMIC's sister company, is the leading provider of software for such analyses.

Before computers were commonplace, media planners had tables which gave reach for various GRP levels depending on demos, dayparts and duplication. These, too, were based on average Nielsen audience accumulation reports.


Tuesday, July 21, 1998 #1966
Sports radio networks rarely, if ever, give CPMs and TRPs for the proposals presented. When asked to provide this info, they cop-out saying "well, other agencies (i.e., JWT, Bozell, BBDO) buy our network." I understand there is a premium to associate yourself with a high profile sports team, but at what cost? Without having resources to evaluate each and every radio station in the network, how can I accurately present these proposals to my clients? Currently, I figure: total market CPP x average rating x number of spots x number of games scheduled + added value = total package value. Am I accurate?

The Media Guru Answers(Wednesday, July 22, 1998 ):
When the Guru buys sports neworks, he gets audience and efficiency data. If you are saying that the networks give national data but not individual market rating, that's a somewhat different issue.If you are buying a team, its value is probably in its home market. If a network is only sold in total, what will you gain by identifying a weak station? If you have all the data to execute your formula, you should do fine.


Tuesday, June 09, 1998 #1886
how do i calculate reach of TV+PRESS, Is there a formula

The Media Guru Answers(Tuesday, June 09, 1998 ):
As a rule, TV and press are thought to duplicate in a random pattern. That is, the random duplication formula is appropriate. The reach of each medium is treated as a decimal. To calculate net reach, we combine the probabilty of each medium's NOT reaching the target, to get the combined probability of neither reaching the target. The remaining people are the ones reached.

The formula works as follows when TV reach is 45 and press reach is 37.

People not reached by TV would be 0.55 of the target

People not reached by press would be 0.63 of target

Total people NOT reached are 0.55 x 0.63 or

0.35 of target.

The remainder of target is reached (1.0 - 0.35 = 0.65)

so reach is 65


Friday, May 29, 1998 #1613
1.what is osto's model? 2.In case of an absence of duplication data for publications, how do l calculate the effective reach using 2 or more media vehicles? in such a scenario, is it safe to use the random theory even if multiple readership is negligible?

The Media Guru Answers(Tuesday, June 02, 1998 ):
1) The Guru is not familiar with Osto's model. It may be specific to India, from where you are writing.

2) The Random method is a starting point. If you can find two other similar publications with measured duplication, you can use the duplication ratio from those publications. If you literally mean "effective reach," that is, reach at or above a minimum exposure level, then you need a more complex formula or a computer program like Telmar's ADplus.


Thursday, May 28, 1998 #1610
1.Please, where can I find "Archives" by topic? 2.I have seen a table showing Awareness Level correlat ed to Target GRPs.Could you, please, tell me how they estimate Awareness Level? 3. I also have seen a table showing Audience engagement in various activities when average commercial is aired. Would you, please, tell me how the information is obtain ed? Is it from a national panel? If yes, does this panel also provide audience data? Thank you, Inocima.

The Media Guru Answers(Tuesday, June 02, 1998 ):
1) The Guru Archives may be accessed from their link on the Media Guru Page. In the next few days, we will be adding a search engine to allow you to find all all past Guru answers on the topics of your choice.

2) The Guru isn't familiar with the table you have seen. Since you are writing from Brazil, it could be based on research totally unfamiliar to the Guru. The proper way for such a table to have been created would use just estimates of awareness, but actual survey results. An advertiser or agency which has conducted many awareness studies and correlated them with actual GRP's of the plans running in synchronization with the studies could create such a table.

In fact, just a few actual measurements could be the basis of a table if it is assumed that the awareness / GRP relationship follows some sort of curve as does the Reach / GRP relationship. The Guru is familiar with one formula for predicting awareness based on GRP, which came from analyzing several plans and surveys. In essence, it predicted that when there was any significant starting awareness, awareness declined in any week where there were less than 100 GRP.

3) Again, Brazil's audience engagement data is not familiar to the Guru. In the U.S. such data usually comes from secondary sources such as our Simmons or MRI, which ask these questions but are primarily print audience and product usage studies.


Wednesday, May 20, 1998 #1599
Dear Media Guru, I am developing and producing a short radio feature for barter syndication. On what basis do syndicators typically set their ad rates? I realize that the rates may be highly negotiable but are there any common formulas (based on CPM, CPP or some other data) used by syndicators to arrive at an "asking price"? Also, can you recommend any resources helpful in developing and marketing syndicated radio programming? Thanks for your help.

The Media Guru Answers(Wednesday, May 20, 1998 ):
Some of the issues in syndicated programming pricing are:
  • CPM or CPP better than spot radio pricing for similar audience size
  • Possible premium for an attractive program environment.
  • %U.S. coverage

There are numerous radio syndication companies, handling everything from Rush Limbaugh to obscure musical formats. One good way to solicit response from -- or tips about -- the right resource would be to post a message about your program to the "Radio Media" discussion list. Send your request to join the discussion to RADIO-MEDIA@adsong.com


Thursday, April 30, 1998 #1578
what is the mathematical relationship between the cpp and cpm, is there any formula linking this two concepts?

The Media Guru Answers(Thursday, April 30, 1998 ):
CPP (Cost Per rating Point) is the cost of a number of media impressions equalling one per cent of a given population group (the specified "target"), as in Women 18-49 CPP.

CPM is the cost of 1000 target media impressions.

Therefore, the mathematical relationship depends on the number of thousands of people who equal one percent the target group.

For example, suppose there are one million women 18-49 in a market, and a radio spot has an audience of 20,000 women 18-49 at a price of $50.

The rating points generated by the spot are 2.0

(20,000 divided by 1,000,000).

The CPP is $25

($50 divided by 2.0)

The CPM is $2.50

($50 divided by 20[thousands])

Since CPP is the cost of impressions equal to 1% of the population, the CPM to CPP relationship is:

CPP divided by 1% of the population in thousands = CPM

In this case, $25 CPP divided by 10 [thousand]= $2.50 CPM

or

CPM times 1% of the population in thousands = CPP

While this works perfectly for national media, it can be tricky in local media unless geography is tightly defined. I.e. a broadcast CPM is usually defined as being on a Metro Area or DMA basis. CPM though, is often based on all impressions generated, even if outside the basic geography. Common geographic population definitions are essential to the accuracy of the formulas.


Wednesday, March 25, 1998 #1553
How can be measurement error calculated? I would like to know is there any correlation between sample size and data validity? Thank you

The Media Guru Answers(Monday, April 06, 1998 ):
Sample size and data reliability are in a "rule of squares" relationship: A sample four times as large is twice as reliable. Note that "reliable" is the statistical term referring to the chances that a duplicate study with the same size random sample will get the same results, give or take a specified range of error.

"Validity" refers to correctness. It might have to do with whether a question asked can corectly produce a result that is desired. For example, a question like "What will you have for breakfast a week from Tuesday?" may not be a valid predictor of what people will actually eat on that day. But, with a proper sample, it will be reliable in predicting with a set degree of variability what people will eat.

The formula for calculation of error for a given sample is:

The Square root of (P x Q over N)

Where:

p = the percentage result to be tested (e.g. 10% of the people will have bacon)

q = the complement, or difference vs 100% (if p = 10% then q = 90%

n = the sample size

So, if a sample of 500 produces the result that 10% will have bacon, the sampling error for this result is

the square root of (10 x 90)÷500 or

+/- 1.342

so the answer of 10% should be read as "between 8.658 and 11.342" and really means that 68% of the time the same study repeated would produce a percent of bacon eaters between 8.658 and 11.342.

If the sample is quadrupled, to 2000, then the error is halved, to 0.671.


Tuesday, December 09, 1997 #1474
How do I put a dollar value on pr media placements? For example, how is a 6 column inch pr mention in the NY Times or a 30 -second mention on a radio station measured in terms of dollars? Is there a formula to use for PR, or do I use the straight advertising rate?

The Media Guru Answers(Tuesday, December 09, 1997 ):
The Guru believes equal space in PR coverage is worth more than an ad, but it's a judgement call how much more.


Thursday, November 27, 1997 #1463
What about wear on and wear out

The Media Guru Answers(Thursday, November 27, 1997 ):
"What about" is a question that invites too broad a response. The Guru has discussed wear out frequently: see Oct 27, below, and the Guru Archives under Media Planning, Media Effectiveness, Media math and Media Research.

"Wear on" is not a familiar term to the Guru, perhaps it is peculiar to Italy, from where this query comes.


Thursday, October 09, 1997 #1427
Does the length of the commercial determine the amount of grps reached? If I schedule a 30ss and achieve X amount of grps, and schedule a 15ss the same amount of times I achieve the same amount of grp's as with the 30ss?

The Media Guru Answers(Friday, October 10, 1997 ):
Very simply, yes. Whether they are watching for 15 or 30 seconds, the audience of the commercial is the same, so the GRPs are the same(never mind theories of channel switching, or we'd be adjusting commercial audiences based on partial viewing).

What can be confusing is that TV buyers often use formulas requiring :15's to be treated as if they had half the rating of a :30 in the same time slot, so that they can most readily calculate a ":30 equivalent" c.p.m. or Cost Per Point.


Thursday, August 21, 1997 #1399
Question: What can you tell me about the mathematical modeling system used in "advanced analytics?"

The Media Guru Answers(Thursday, August 21, 1997 ):
Advanced analytics is a general description of new techniques of modelling, the key to which is use of real data. Not just sales, as a dependent variable, but real quantification of all the elements of marketing mix: media weight, budgeted coupon redemption, price promotion, etc., as independent variables.

Each practitioner will have proprietary formulas to determine what spending on what elements produces desired sales results. The simple explanation is assembling all the facts pertaining to a situation and letting the "answer" emerge of its own accord, rather than hypothesizing an answer and looking around for supporting facts.

The let the answer emerge from the facts approach is quite old, what is new is the computer-supported capability to maniipulate more data in more ways, and have real results against which to judge outcomes.


Thursday, June 19, 1997 #1366
Dear Guru, I have a set of urgent questions to ask of you. I have a meeting tomorrow, and need your help! 1. How is effective reach calculated? 2. Reach v/s Frequency -- when should one be given priority / importance over the other? 3. Is there any way of taking creative into account while analysing competition? If yes, can a system of weights be worked out? 4. How do you reconcile to the vast difference between reach/frequency deliveries from a Peoplemeter system as opposed to the Diary system? My client refuses to accept a 4+ reach of 30% being accustomed to levels of 70% for the same plan! Would greatly appreciate your immediate reply.

The Media Guru Answers(Thursday, June 19, 1997 ):
1) In any schedule of several commercials, some of the target group will see only one, some will see two, some will see three, some will see four, some five, etc, etc.

The actual measurement is based on tracking the cume of several different advertisers schedules in a single measurement period such as one month of the PeopleMeter.

A mathematical model that will match the measured GRP/Frequency is calculated so that plan deliveries can be predicted. Going more deeply into the actual measurement, it can be determined how many people of each demographic group were exposed to each commercial in the schedule and a model calculated which will predict that performance for a plan.

For example, below is the typical output of a computer models' frequency distribution, showing what percent of the target saw exactly n commercials and what percent saw n+. (this example is from Telmar's ADplus):

                    Frequency (f) Distributions 
                           ------------------------------------- 
                                  % who saw
                                 ---------------
                          #seen exactly  at least     
                          ----- -------  -------
               Target:      f     rch    rch    
               P18-49      ---   -----  -----   
                            0     69.1  100.0   
                            1     11.5   30.9    
                            2      6.0   19.3    
                            3      3.7   13.4   
                            4      2.6    9.6   
                            5      1.8    7.1    
                            6      1.3    5.2   
                            7      1.0    3.9   
                            8      0.7    2.9   
                            9      0.6    2.2   
                           10+     1.6    1.6   
                           20+     0.0    0.0    

2) Reach vs Frequency: The determination of emphasis here can be a complicated analysis making up the greater part of a plan's documentation, under the heading of "communications strategy." A commercial so powerful that it's sell is overwhelming in one exposure might take the "Let's buy one spot in the Superbowl" route as did the Macintosh computer with the classic "1984" execution.

In more competitive situations, competitors' levels are taken into account, clutter in the media of choice, copy quality, etc. Obviously a balance must eventually be struck between reach and frequency based on judging all these factors.

3) There are several ways to take creative into account while setting up reach vs frequency goals;

The complexity or simplicity of the message

The number of commercial in the pool

how close your commercial is to the established "wear-out" level

The balance of :30 to :15

etc, etc. can all be assigned factors and totalled or averaged to give a reach vs frequency emphasis factor

a similar exercise can also set effective frequency thresholds

4) There should not be "vast" differences between effective reaches based on people meter and diary systems if schedule GRP and other aspects are the same. 5 or 10% would be the range the Guru would expect.

A plan with a 70 reach at the 4+ level would be delivering in the range of 98% total reach. It sounds as if your client may be confusing a plan with 70 reach and an average frequency of 4 with 70 at an effective frequency of 4. Or perhaps confusing 4-week reach with a long term cume?


Tuesday, May 13, 1997 #1345
Since "PRICING WEB SITE ADVERTISING" was first published (it's not dated but I'm guessing '96?) have there been any 'advances' in the methodology for pricing web advertising beyond either the ModemMedia model or the alternatives suggested? I am not an advertising professional (and they said us geeks use obscure achronyms?), and I am also looking for a concise FAQ type document that might explain the formulae and jargon (CPM, Frequency, Impressions in your excellent on-line dictionary and Depth which isn't) within the context of web advertising. Are there and other specific media terms (new or old) that are pertinent in a web advertising context (I got page view and hits)? Thank you.

The Media Guru Answers(Wednesday, May 14, 1997 ):
The AMIC article was wriiten in the latter part of 1995, not long after the appearance of the Internet World May 1995 article which it discusses.

By the way, please be aware that AMIC has added a new area, called I-Trac, which discusses web terms and measurement and which includes a Web Glossary

In terms of newer thinking, consider the critqued article's central concepts:

1.Determine the ratio of hits between the web site's log and the number of file "hits" that make up the page carrying the ad. Divide logged hits by number of hits making up the page to calculate what we can call "page views." Then call page views "reach."

Since then, the software which interprets log files has developed so that it can distinguish pure "hits" from the more relevant page requests or "page views" . Hits today is taken to refer to any line in a log file, even errors. (Ad) Page requests is the analog to traditional media's "impressions".

2.Determine repeat viewing of that page and call that frequency.

We more commonly use "frequency" in terms of whole campaigns

3.Determine the success of viewings of that billboard ad in moving readers to the actual web site and call that "depth."

This measurement concept has come to be called "click-through" or ad click rate. Depth was a term only used as defined in this Internet World article.

Today pricing is generally based on cost per thousand (CPM) impressions. Rates seem to range from $15 cpm for the broadest, general audience sites' rotating banners, through $50 or so for search engines' keyword banners up to $100+ for "premium audience" on highly targeted business to business web sites. Another pricing model growing in popularity is "price per click," which charges for each vistor who clicks on a banner. The problem here is that the site hosting the banner must rely on the creative to generate viewr response -- it isn't all the effect of the web site itself. Therre is considerable literature today about how to influence clicks, as well as a growing body of research which argues for the awareness building effects of the banners, regardless of clicking response. Finally, simple revenue based models are the rising concept. In this, sites hosting banners are compensated with a portion of the transaction revenue generated by web surfers they send to retail type sites. An offshoot of this is a model for ad placement agency compensation based on the revenue generated by their placement of ads at recommended sites.


Thursday, March 20, 1997 #1013
Dear Guru,What in your opinion are the personal qualities andprofessional qualifications for a media planner? Thanx

The Media Guru Answers(Thursday, March 20, 1997 ):
The Guru believes the the key personal qualities are an eagerness to learn, and ability to learn and and openess to new information.

Professional qualifications today include

-good mathematical skills, e.g. ability to rough-estimate percentages without a calculator, to avoid being overly reliant on computer output.

-Computer skills

-Writing skills, especially the ability to explain though processes logically and clearly


Wednesday, January 29, 1997 #1065
I'm finding very hard to calculate the price of an advertise on the web.DO have any tip or formula that could help me ? Thank you very much !

The Media Guru Answers(Thursday, January 30, 1997 ):
What information or goal are you starting with? As a guide line, search engine keyword banners may cost between $30-$70 per thousand ad impressions.


Monday, January 27, 1997 #1067
My client is requiring me to use adjustment percentages whencalculating grp's in print. I was always taught that reach x frequency= GRP's. Now if I calculate the adjustment to my grp's, the formula no longer works. Is this correct, or do I have to do something else to my reach/frequency? Help!!!

The Media Guru Answers(Tuesday, January 28, 1997 ):
There are various approaches. If the GRP adjustment is just an index reflecting characteristics of the vehicles and their audiences, it may be sufficient to show R/F/GRP/AdjGRP

If the adjustments are meant to change actual value of the GRP, it is usual to recalculate reach from the new, adjusted GRP. Since print r&f is usually calculated from actual schedules, via a "black box" algorithym, rather than from a grp "curve," this may be impractical. If your system allows you to enter factors for each publication before calculating reach, that may solve your problem.

Lastly, even with adjusted GRP to represent some abstraction, the people reached would not be reached at a different average frequency, so one quick and dirty answer, if you must use adjusted grp, is just to divide them by the original frequency, to get reach.

It's similar to the concept of changing a spot coverage area, broadcast r/f to its national equivalent: The GRPs are weighted by the coverage area % and the frequencyremains constant, to calculate the reach.


Friday, December 20, 1996 #1090
Media Guru:
What can you tell me about standard error? Specifically, I have three questions:
1. What goes into standard error? If not the actual calculations, can you tell me what affects standard error: it's not just sample size, is it?
2. What is the maximum standard error that is considered acceptable to the media -- specifically, the advertising -- industry?
3. Related to the previous question, do you happen to know recent standard error levels for suppliers such as Nielsen (National), Simmons or MRI?
Thank you for your attention to this humble query.

The Media Guru Answers(Saturday, December 21, 1996 ):
As the adjacent answer to your previous Guru inquiry details, standard error considers sample size and the size of the specific response. Standard error is smallest for a 50% response in a specific way. 10% or 90% answers have the same standard error. When you hear that a study, like a presidential poll is "+/- 3% that is usually the standard error for a 50% response.

It is interesting to note that the size of the sample is the key and not the relationship of the size of the sample to the universe. In other words, when a broadcast rating service uses a larger sample for New York than for Klamath Falls it does so because of the cost of larger samples being more affordable by larger market's media who sponsor the research, not because a bigger market "needs' a bigger sample. Also note that because of the square root aspect of the calculation, a sample must grow by a factor of 4 to reduce error by half.

"Minimum acceptable error" is quite situational. While an error of +/- 2 on a rating of 10 seems small, it becomes important when a buyer need to decide between programs rated 8,9,10,11 and 12 which might all have identical audiences yet seem to vary by 50%.

As stated above, sample size and response control standard error. Neilsen Simmons and MRI each give the information with their reports to calculate error appropriate to the individual report and findings. Most software used to generate reports has the option to display the error witheach cell of data reported. (You may have noticed single and double asterisks on tabulations of Simmons or MRI data, these are indicators of standard error ranges)


Tuesday, December 17, 1996 #1092
Dear Media Guru Guy:Where can I find out more info on standard error? First, how is it calculated, or what affects standard error? Second, I'm thinking about magazine readership research, and I'm wondering what standard errors some of the popular studies have (MRI or Simmons, for example). And then, I'm also curious as to what, among media gurus, is considered an acceptable or unacceptable error. Do the same standards apply for other media research studies, for example, Nielsen ratings? Thanks Mr. Guru.

The Media Guru Answers(Friday, December 20, 1996 ):
Standard error reflects the range of "tolerance," due to sample size, around the reported answer where the "truth" lies. Inother words, statistical data like "10% of women 18-49 read MagazineX" in reality means that within the range of error expected, if thesame study were repeated 100 times, with a sample of 225, the resultwould between 8 and 12 percent, 68 times out of the 100.

The formula isthe square root of (P times Q divided by N)

Where
P= the percentage to be tested
( e.g. the 10% in the Guru's example, above)

Q=100 minus P ( 90% in our example)

N= total sample size (225 in our example)

or

10 X 90 = 900

900 divided by 225 = 4

square root of 4 = 2

One standard error is the amount of variance sampling causes 68% of the time.

So, at one standard error, 10% is between 8% and 12%with 68% "confidence" At 2 standard errors or within+/- 4 points, or6 to 14% we have an answer we are confident our research will repeat95% of the time. This is why the concept is also referred to as"reliability". It is really way to express confidence that the samesampling procedure will produce the same result.

Most statistical texts can give you considerably more on the topic.


Monday, August 05, 1996 #1171
In regards to print advertising, what is a wear-out report? What data do I need to complete this report (reach, frequency, formulas)?

The Media Guru Answers(Thursday, August 08, 1996 ):
The Guru has discussed Wear Out previously (see below July 17 and May 7).

A wear out report would state the status of various print executions in your campaign in comparison to the wear out standard you have established.

Clients have a way of asking the wear out question without setting a standard or even being able to decide how to set one.

Essentially an ad is worn out when it loses all or most of its ability to accomplish its marketing purpose with its target. The purpose may be as simple as product sales, or lead generation in a direct response campaign, or it may be as difficult to define as building brand imagery or awareness of a specific product benefit. Since directly relating any of these to a specific ad would require custom research, it is typical to use whatever research has been done in the past as related to easily modelled media measurements, such as reach, frequency, GRPs or quintiles.

For example if in the past, a custom study showed the average ad was worn out at a time when the planners knew that 80% of the target had seen it 8 or more times, or when the frequency in the top 2 quintiles passed 30. (Don't use these examplenumbers). Naturally, different ads perform differently, but you will need to work on an average basis.

A wear out report then becomes a matter of reporting something like how many of thetarget have seen the ad at least "x" times, or that the frequency in the top 2quintiles will exceed the standard measure as of a certain month of the schedule, or"X" number of GRPs will have run for the ad by some date.

The key is knowing how one of these media measures relate to your wear out standard. Then the report is a simple task.


Thursday, June 27, 1996 #1188
Is there an established formula for setting rates for non-url linked advertising on web pages (i.e. display only advertising with no links to other sites)?

The Media Guru Answers(Thursday, June 27, 1996 ):
Nothing "established," but there are some good insights at the following sites:San Jose Mercury News' "Advertising on the World Wide Web With Mercury Center"Newspaper Advertising Association: Tracking Audience on the Web, by Jim ConnaghanAMIC Research Monitor: Pricing Web Site Advertising, A Media Buyers View by Abbott Wool


Wednesday, May 08, 1996 #1224
I am composing my first interactive media plan for a regional bank client. It is a three month campaign. I am trying to set a monthly gross impression goal that would generate adequate on-line exposure for launching a pc based banking product. Any rules of thumb?

The Media Guru Answers(Wednesday, May 08, 1996 ):
You could try to "back into" your goal.

How many customers for the PC product would be considered a "success?"

What response rate can you expect from a web site?There may be some published infromation in the trades.

Suppose it's the 1 - 1.5% that's considered successful in some other direct response media. Divide your customer sign-up goal by the response rate to project needed site visits. For example, if you want 1000 pc accounts, 1000 divided by .01 (1%) is 100,000.

Is this realistic? If there are 10 million US households using the WWW (a mid range estimate) how many might be in the "regional" service area of your bank? We assume there is some need for a personal visit to the bank at some point in the process.

Let's take a generous estimate of 10%. So there would be 1,000,000 potential customers. You would need to draw 10% of them to your site to get the 100,000 vistors who would produce the 1000 accounts.

This certainly indicates that you would need a strong traditional media campaign to draw site visitors.

But, plug in your own numbers in the suggested process, and as the saying goes, "you do the math."


Tuesday, April 30, 1996 #1232
Can you recommend any good books on how to plan/negotiate/buy national broadcast. My experience is only in print and spot TV so I need a good book to get me up to speed. Thanks in advance.

The Media Guru Answers(Tuesday, April 30, 1996 ):
There are a few books on planning, such as Sissors and Bumba's "Media Planning." Negotiating and buying is more a matter of apprenticeship and seat-of-the-pants learning. While essential principals of National Boroadcast are similar to spot, there are many differences in details, like guarantees, "re-caps," special math applications, etc. Your best best would be to befriend a salesperson in each medium and get a quick course in the special issues that apply, assuming there is no one to guide you in your own company.


Friday, March 08, 1996 #1266
Guru:Is there a formula for calculating reach & frequency for trade vehicles.

The Media Guru Answers(Sunday, March 10, 1996 ):
There is no truly simple formula for calculating reach and frequency of any medium. The key datain print R&F are pair-wise duplication between different vehicles and between two or more insertions in the same vehicle.

As the number of insertions in a plan increase, the number of data elements to include in a formula increase. The number of possible pairings for just a 10 insertion plan is 45 ((n x n-1) / 2).

Telmar among others, offers software designed to quickly perform these calculations on defined schedules of media measured by SMRB, MRI, MMR, J.D. Power or others. Using measured media as prototypes, reach of various schedules you might want to consider could then be calculated. From these numerous calculations, you could, by regression analysis, develop a "simple" formula of the form y=ax+b to calculate frequency based on GRP of typical plans of the sort you run in these media (y is frequency; x is grp; a and b are factors from the regression).

A formula of this kind is very specific to the audience dynamics of the media vehicles involved. Please understand, this is not a recommended technique, merely a response to your question.


Friday, March 01, 1996 #1270
I work for a company that sells a braod range of complextechnical products. In developing a new lit fulfillmentstrategy (first there were printed brochures, then faxback, then ...) I have a few questions:
1. Can you direct me to Web sites that have done a goodjob of providing info/data sheets (ie.designed to obti-mize WEB capabilities not just slapping up existing material)?
2. What about customizing? eg. Cust completes request that indicates "I'm considering widgets produced by X,Y,&Z." Then delivering info sheet that shows comparative"feeds and speeds" of X,Y,&Z's widgets. Do you know of successful examples of this? Any pitfalls?
3) How to make sure to deliver "value added" material?

The Media Guru Answers(Sunday, March 03, 1996 ):
You're not asking a media question here, but. . .

Using Alta Vista to search the word "submit" , which appears on just about all forms pages, found half a million such web pages, of which the first 10 were mostly technical. You be the judge of which of the half million are good or bad:


Wednesday, February 21, 1996 #1755
Dear Media Guru- I have a two part question , both dealing with the same subject, tv sampling error. Suppose ER gets a 20% rating and Seinfeld gets an 18%, both off a sample of 1000 resondents. What are the odds of there being absolutely no difference between these two ratings? This is not as simple as looking up the standard error of each rating. I remember that it has something to do with the standard error of the difference, but I just can't recall the calculating process.Could you please explain? Then to complicate matters, I'm looking at the same phenonena on a grander scale. Suppose the estimated delivery in rating points for a tv schedule is 1000 grps and it underdelivers by 10%- ie. 900 grps. What is the likelihood that the difference had to do with pure chance ( sampling error) and how do I calculate that? I know this is more difficult since you have to account for buying many programs in the estimate and the actual. Naturally, we are assuming that the error differences are all due to sampling, and not the idiosyncrasies of the marketplace or the impurity of the sample. In this case I know the answer is going to be technical, but that is what I need. Thanks

The Media Guru Answers(Friday, February 23, 1996 ):
The Guru loves this kind of stuff. The answer is technical but hopefully, in simple terms.

First, if ER has a 20 rating and Seinfeld has 18, with a sample of 1000 (for that demographic), then the ER 20 rating's standard error is +/- 1.265 while Seinfeld's 18's is 1.215 (See formulas in the Jan 25 18:23 Guru Q&A below).

Note that the absolute size of the error on the 20 is larger but it is relatively smaller. Also note that the range of these errors is such that they can make the two programs' ratings equal: 20 - 1.265 = 18.735 which overlaps 18 + 1.215 or 19.215.

There is a 68% probablity that these two ratings fall within this range. But the swing could go either way on either number. And could fall anywhere within the +/- range specified

There is a 90% probabilty that these two ratings fall within +/- 1.999 on the 18 and +/- 2.081 on the 20. The odds are 95% that they fall within +/- 2.381 for 18 and 2.479 for the 20.

These odds actually relate to reliabilty. That is, if you repeat the same rating study 100 times with the same actual facts existing, 68% of those studies will give ER a rating between 18.735 and 21.265.

Now the 1000 GRP underdelivered by 10% is different As the beginning of the explanation showed, while there is a swing around any rating (a 5 would be +/- 0.689 in the same study), the odds equally favor underestimates and overestimates. This is the same as the reason why small samples don't necessarily underestimate ratings. So in 1000 GRPs made up of 500 spots with an average 2 rating, the sampling error on the individual ratings somewhat cancels out.

To calculate this in an Arbitron measured radio buy using a single survey and one station, for example, the formula is

GRP x ((100 x #spots) - GRP) / sample x Factor)))

"Factor" is from a table provided, specific to demographic and #quarter hours in the daypart of the buy.

So, if your 1000 GRP were based on Adults 18-49 ( with a 1000 A18-49 sample), and a Mon-Fri, 6a-7p schedule, the calculation would be:

(1000 x ((100 x 500) -1000) / (1000 x 2.42)))

or +/- 143 GRP at the 68% confidence interval. Obviously, if the average rating were higher, hence fewer spots or if the sample was larger the variance would be smaller. With an average 20 rating, the swing is about +/- 40 GRP.

So, depending on average ratings and sample sizes, the 10% underdelivery could be within the range of standard error.


Friday, February 16, 1996 #1760
Dear Mr. Guru, Thank you for your last reponse on how to calculate GRP's. You had mentioned that you had explained it fully except for Neilson's calculation methodology. I would be interested in hearing more about this method of calculation as well. Also, is there a "better" way to measure the actual "Impact" an ad campaign has had if you know the actual length of each ad, the frequency the ads ran and the channels(and shows) that they ran during. ie. frequency X length X Audience(rate for each time slot)?? This is obviously a simplified formula, but your feedback on this would be greatly appreciated. Lastly, for television advertising, what are some of the other accepted methods of measurement. Thanks (Again) darrylw@conceptus.on.ca

The Media Guru Answers(Friday, February 16, 1996 ):
It is Neilsen's survey methodology that wasn't covered. They would use the same calculation formulae. The full description of Neilsens methodologies for People Meter, household meter and diary would cover several pages. Contact Neilsen who will be happy to send you methodology booklets.

Regarding "impact" there are as many ways to evaluate this as there are advertisers.

Some advertisers use a factor for copy length based on norms from recall tests. For example, 75% of a :30 is a typical value for a :15.

Some use attentiveness by daypart.

Some use a combination of the two factors.

Some apply the factors to GRP as an indicator; some apply to GRPs and then estimate reach from those adjusted GRPs as an impact indicator.

The frequency of a schedule, as discussed so far, refers to the average frequency of exposure for all pesons reached.

There are those who use "effective reach," counting only persons reached at least 3 times (or any designated minimum) when evaluating the impact of a schedule.


Thursday, February 15, 1996 #1761
I would like to know a DETAILED calculation for GRP's for Television advertising. I assume the frequency is the number of times the ad ran across all channels. But how do I calulate the Reach for a T.V. AD. Is it based on the rate cards of the networks?(if so, how) or is it based on direct audience measurement. As much detail as possible would be greatly appreciated. darrylw@conceptus.on.ca

The Media Guru Answers(Thursday, February 15, 1996 ):
Calculation of GRP does not depend on knowing reach, though reach x frequency is ONE formula. Reach is the more complex calculation, GRP is relatively simple (see other formulae in the adjoining question).

Reach has no relationship at all to rates, nor to commercial length, for that matter. Audience research surveys such as Nielsen can tell us the audience of individual programs. The net unduplicated audience, or reach, of actual advertisers' schedules, examined over time covered by a given survey period, typically four weeks, can be determined.

When many such scehdules, usually thousands, have been examined in that way, "curves" on a graph can be drawn representing the intersections of reach values with schedules' GRPs. The graph curves because each added announcement adds fewer new, unduplicated people toi the reach of the schedule.

The curve can be expressed as a formula y = ax+b, which then can be built into the computer model which media planners use to quickly calculate reach from given GRPs and sometimes other descriptive details of scheduling, such as average ratings, numbers of different networks or programs, etc.

The Guru is now nearly out of details unless Nielsen survey methodology is of interest.


Thursday, February 15, 1996 #1762
What is the actual formula for calculating GRP's

The Media Guru Answers(Thursday, February 15, 1996 ):
There are various formulae, depending on from what data you are working:

GRP = Reach x frequency

or

GRP = Average rating x number of advertisements

or

GRP = The sum of the ratings of all the advertisments in a schedule

or

GRP =The total impressions delivered (i.e. audience among a specific demographic group, expressed in raw numbers of people X number of advertisements) divided by population universe for that demograpic.


Thursday, January 25, 1996 #1774
I have a total universe of 9500 people and I would like to know how big a sample I would need for as good study. This is for a phone interview.

The Media Guru Answers(Friday, February 02, 1996 ):
The population size is a relatively insignificant factor in calculating reliability of a sample; 500 respondents is just about as reliable in surveying a small town as for the United States as a whole.

To plan a "good study," you need to consider the size of the typical answer you will get.

If your typical response will be 50% of respondents said "yes" then a far smaller sample could be suitable than if answers are "10% use brand B."

You also need to decide what level of reliabilty you require, or how much swing, +/-, is acceptable and to what tolerance.

For example:

If your sample size is 500, a 50% answer is actually reliable +/- 4.4 percentage points, 95% of the time and +/- 3.7 points 90% of the time.

If the sample size is 125, a 50% answer is reliable +/- 8.8 points, 95% of the time. This is double the relative error of the 500 sample (rule of thumb, 4x as much sample reduces error by half).

If the answers anticipated were 10%, then for the 125 sample it varies +/- 5.2 points, or over 50% relative error.

A 10% answer from a 500 total sample yields +/- 2.6% points at 95% tolerance or 26% relative error, which is possibly acceptable for your need.

To examine other possibilities, the formula for 95% tolerance is:

1.96 x squareroot of ((PxQ)/N)

where

P = the answer size expressed as a decimal fraction
Q = the remaing fraction of the sample
N = the total sample size

To examine 90% tolerance, substitute 1.645 for 1.96


Thursday, January 04, 1996 #1802
How do television and radio advertisers value an impression? That is, if someone advertises on television is there a formula used to determine prices for :15, :30 and :60 spots? Thanks.

The Media Guru Answers(Friday, February 02, 1996 ):
As a general rule, :30 impressions are the standard reference for TV and :60 for radio. "value" and "price" may or may not correlate:

In TV, a :60 is usually double a :30's price but has the same value in reach. Some advertisers use attentiveness or recall factors to adjust the "value" of a :60 vs a :30 impression. Your question focuses on pricing.

In most cases, :15's are priced at 50% of 30's, but there are instances where 65 or 75% is used.

In radio, :60 is the standard, with :30's typically priced at 80-85% and :15's not in use. Some stations today, especially top rockers with a sensitivity about clutter and inventory sell "units" not differentiating between :60's and :30's in price.



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