Following the birth of TV and the adoption of TV ratings that followed, gross rating points (GRP) became the universal tool for media planning and reporting across many forms of traditional media. But what is GRP for online, also known as iGRP? Unlike TV, there is no rating for online content, so how is iGRP calculated?
While the original rating point system was developed to evaluate the popularity of TV programs, advertisers were early GRP adopters for its use as a common currency when buying and measuring TV advertising. In the beginning, advertisers went through a painstaking, manual process of multiplying the number of insertions with each rating point and then adding all of this together to calculate GRP. Later, smart media planners developed a simpler formula using reach and frequency to calculate GRP.
GRP = % reach x frequency x 100
For example, a television advertisement that that reached 40 percent of W25-54 at a frequency of 5 times equates to 200 GRPs.
Does this equation mean that TV GRPs and online GRPs can be added together and then used for cross-platform delivery? If only it were so easy.
A new white paper from BrightRoll sets out to answer this question by investigating the formula developed for traditional TV and the implications of parallel online universes from comScore (in the US and Canada) and Nielsen. The paper also explores how to build from the origins of GRP and current digital audience measurement sources to provide advertisers with consistent, proven standards to efficiently plan and measure their campaigns across the new digital viewerscape.