Audience measurement measure how many people are in an audience, usually in relation to radio listenership and television viewership, but also newspaper and magazine readership, and increasingly, usage of websites. It ion, to help broadcasters and advertisers determine who is listening, rather than just how many. This broader meaning is called audience research.
Measurements are broken-down by media market, which for the most part corresponds to metropolitan areas, both large and small.
Ratings point is a measure of viewership of a particular television program.
One single television ratings point (Rtg or TVR) represents 1% of viewers in the surveyed area in a given minute. As of 2004, there are an estimated 109.6 million television households in the United States. Thus, a single national household ratings point represents 1%, or 1,096,000 households for the 2004-05 season. When used for the broadcast of a program, the average rating across the duration of the show is typically given. Ratings points are often used for specific demographics rather than just households. For example a ratings point among the key 18-49 year olds demographic is equivalent to 1% of all 18-49 year olds in the country.
A Rtg / TVR is different from a share point in that it is the percentage of all possible viewers, while a share point is 1% of all viewers watching television at the time. Hence the share of a broadcast is often significantly higher than the rating, especially at times when overall TV viewing is low.
GRPs / TRPs
Gross rating points (GRPs) or Target Rating Points (TRPs) are chiefly used to measure the performance of TV-based advertising campaigns, and are the sum of the TVRs of each commercial spot within the campaign. An ad campaign might require a certain number of GRPs among a particular demographic across the duration of the campaign. The GRP of a campaign is equal to the percentage of people who saw any of the