Gross rating point


In advertising, a gross rating point is a measure of the size of an advertising campaign by a specific medium or schedule. It does not measure the size of the audience reached. Rather, GRPs quantify impressions as a percentage of the target population, thus this percentage may be greater, or in fact much greater, than 100. Target rating points express the same concept, but with regard to a more narrowly defined target audience.
GRPs are used predominantly as a measure of media with high potential exposures or impressions. Nielsen Media Research is an example of a company which uses GRPs.

Purpose

The purpose of the GRP metric is to measure impressions in relation to the number of people in the target for an advertising campaign. GRP values are commonly used by media buyers to compare the advertising strength of components of a media plan.

Construction

GRPs are most directly calculated by summing the ratings of individual ads in a campaign. If a television program has an average rating of 7, and an ad is placed on 5 episodes, then the campaign has 7 × 5 = 35 GRPs.
GRPs are simply total impressions related to the size of the target population:
GRPs can also be related to measures of the reception of the ad campaign. If an ad campaign results in 50% of the target seeing the advertising 3 times on average, then the campaign's size was 150 GRPs: