Gross rating point
Gross rating point (GRP) is a term used in traditional 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). 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%).
GRP values are commonly used by media buyers to compare the advertising strength of various media vehicles.