Gross rating points measure the total weight of a campaign. One GRP equals one percent of a target audience receiving one impression. Reach multiplied by frequency gives you GRPs, which is why two campaigns with the same GRP total can look completely different in practice.

Broadcasters and media buyers use GRPs to compare buys across programs and dayparts. A buy with 200 GRPs might reach half the audience four times, or eighty percent of the audience two and a half times. Same number, different outcome.

Related metrics

• Target rating points, focused on a specific segment
• Impressions, the raw count of ad views
• Reach, the number of unique people exposed
• Frequency, the average exposures per person

GRPs are a planning tool, not a performance guarantee. A high GRP total with weak creative still fails.