Measurement & Metrics

Gross Impressions / GRP (GRP)

The total of all impressions including duplicates (one person counted each time exposed). Gross Rating Points (GRP) express gross impressions as a percentage of a target population.

Also known as: GRP, gross rating points

Related terms

Impression A counted exposure of an ad to a person. In DOOH it is the foundational unit of currency, but the exact definition varies by standard — from a raw play, to an opportunity-to-see, to a viewability-qualified audience impression. Reach The number of distinct individuals exposed to an ad over a period, counting each person once. Best measured on the basis of audience impressions. Frequency The average number of times a single individual is exposed to an ad over a period. Long dwell times in beauty venues naturally raise frequency per visit.