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Guru Search Results: 4 matches were found

Wednesday, December 18, 2002 #5693
Dear Guru: When estimating GRPs for a media plan, what is considered an acceptable error level (10%, 15% or more)? Thanks, R.

The Media Guru Answers(Thursday, December 19, 2002 ):
The Guru presumes you actually mean the ratio of post buy delivery to plan, since plan specifications are prescriptions, rather than estimates. In any case, it is a judgement, but 10% is a common tolerance.

Friday, February 12, 1999 #2328
Our agency has had some recent difficulty in posting about 90% is some spot markets. We are looking for research and/or articles that say whether other agencies are having trouble as well. We have read some research that talks about network erosion -- but nothing that mentions how this relates to post buys. Any thoughts?

The Media Guru Answers(Monday, February 15, 1999 ):
The Advertising Research Foundation library will have information published on the topic.

The Guru doubts that network erosion is a part of your problem, unless you are buying mostly day and prime on affiliates and doing buys and estimates a couple of years ahead of posts.

The ability to post within 90% depends on two factors

  • The accuracy of buyers' estimating techniques, and
  • the stability of program performance

Network erosion is small but steady and easy to allow for in projections. Buyers' estimates are usually primarily based on historical usage trends and most recent share performance plus some intelligence about programming changes. Unless there are very volatile schedules, estimates should be within +/- 10%. Some will be over by more and some will be under by more, but these should balance. Some buyers may be overly optimistic, so that buys appear to come in on goals, but this practice causes just the sort of post-buy problems you seem to be facing.

Friday, July 17, 1998 #1959
I am working on a television post buy analysis and was wondering what the industry standard index is for estimated vs. actual GRP ratings? Rule of thumb in the past was 90%+, is this still in effect and does it change from market to market? Is there any documented research for this percentage or do most television sales reps know the "rules" in order for me to get make-goods for my client?

The Media Guru Answers(Friday, July 17, 1998 ):
Everything is by agreement. In this business, one tends to think the policy of the agency or medium where they learn things are rules of the industry.

Some agencies have a +/- 15% policy others have +/- 10%. Some advertisers make their agencies give them +/- 10% when the agency policy is a wider allowance and some major advertisers don't post.

Some network deals are 100% guaranteed, magazine "rate base" is 100% guaranteed, but many advertisers/agencies never verify delivery.

If you negotiate a 90% deal with your sales rep, then that' s what he/she's got to do. If you're doing regular business, it shouldn't be much of an issue to get 90%, anyway.

In markets where there are weekly ratings available, it should also be your practice to rerate buys as they progress and negotiate adjustments during the schedule to avoid shortfalls on post analysis.

Monday, May 19, 1997 #1349
What is the standard rule for averaging breaks when doing a television post buy analysis? Some television stations are telling us it's a 15 minute before and after window.

The Media Guru Answers(Monday, May 19, 1997 ):
The Guru agrees that the best way to average a break position is generally by averaging the preceding and following quarter hour measurement. However, Nielsen also reports "break" audiences in the time period section of their report. Some agencies make a policy of using this break rating when a spot airs within ±2 minutes of the exact break time or some other acceptable standard time tolerance.