Online marketing metrics : Gross rating point

Many of the basic tenets of traditional advertising apply online. David Smith, CEO Mediasmith, identifies three of these basics as reach (of an ad/campaign), the frequency the ad is shown/seen, and a term that may be new to many online marketers: gross rating point (GRP). GRP represents the percentage of the target audience reached by an ad. For example, an ad that airs three times reaches 30 percent of the target audience, it is said to have a GRP of 90 (frequency x percentage reach).