1. The total number of in-market impressions delivered by an Out of Home display expressed as a percentage of a market population. One rating point represents impressions equal to 1% of the market population. In the calculation of GRPs, total impressions must first be reduced to the in-market impressions of individuals who live in the defined market and are part of that market’s population base.
2. Rating points for other media are based on opportunity-to-see audiences and not audiences viewing advertising.