[Seaduction]

Gross rating point (GRP) is a term used in advertising to measure the size of an audience reached by a specific media vehicle or schedule. It is the product of the percentage of the target audience reached by an advertisement, times the frequency they see it in a given campaign (frequency × % reached).[1] For example, a television advertisement that is aired 5 times reaching 50% of the target audience each time it is aired would have a GRP of 250 (5 × 50%). To achieve a common denominator and compare media, reach x frequency are expressed over time (divided by time) to determine the 'weight' of a media campaign. GRP's are used predominantly as a measure of media with high potential exposures or impressions, like Outdoor in particular, then broadcast.

GRP values are commonly used by media buyers to compare the advertising strength of various media vehicles.[2]