Measurement · also called GRP, TRP (target rating point)
Gross rating point (GRP)
A gross rating point (GRP) measures advertising weight: reach as a percentage of a target population multiplied by average frequency, so 1 GRP equals impressions equal to 1% of that population.
GRPs come from TV planning. If a campaign reaches 40% of the target audience with an average frequency of 3, it has delivered 120 GRPs. It is a way to express how much advertising pressure a campaign applied, independent of the number of spots.
Target rating points (TRPs) are the same calculation for a specific demographic, such as adults aged 25 to 54. Buyers traditionally plan and buy Linear TV in cost per GRP or cost per point, using audience measurement panels. Digital and CTV have adopted similar concepts to allow cross-media comparison, with the MRC setting standards for cross-media audience measurement.
GRPs have limits. They do not distinguish between reaching many people once or a few people many times, so planners also look at reach and frequency separately. They count opportunities to see, not attention or outcomes. And when digital impressions are converted into GRPs, invalid traffic must be removed and duplicate reach across devices handled, or the numbers will be inflated.
Think of it like this
GRPs are like measuring rainfall in millimetres: they tell you how much fell in total, not whether it soaked everyone a little or a few people a lot.
An example
A detergent brand in India plans 300 TRPs among women aged 25 to 44 over four weeks: for instance, 60% reach at an average frequency of 5.
Related terms
Reach and frequency
Reach and frequency are paired metrics: reach is how many different people saw an ad, and frequency is the average number of times each of those people saw it.
Reach
Reach is the number (or percentage) of unique people or households who saw an ad at least once during a campaign, as opposed to the total number of impressions.
Linear TV
Linear TV is traditional scheduled television, broadcast, cable or satellite, where viewers watch programmes at the time the channel airs them, with ad breaks sold to all viewers of that channel.
Upfronts
Upfronts are annual events and negotiations, mainly in the US, where TV networks and streaming services present upcoming programming and advertisers commit budgets in advance for the coming season.
MRC (Media Rating Council)
The MRC (Media Rating Council) is a US non-profit industry body that sets measurement standards and audits and accredits media measurement services, including viewability and invalid-traffic filtering.
Sources: MRC standards and guidelines