Audience Measurement - Ratings Point - GRPs/TRPs

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, multiplied by the average number of spots that these viewers saw. Targeted Rating Points are a refinement of GRPs to express the reach time frequency of only the most likely prospects. For example, if a campaign buys 150 GRPs for a television spot, but only half of that audience is actually in the market for the campaign's product, then the TRP would be stated as 75 to calculate the net effective buy .

Gross rating point, a standard measure in advertising, it measures advertising impact. It is a percent of the target market reached multiplied by the exposure frequency. Thus, a program which advertises to 30% of the target market and gives them 4 exposures, will have 120 GRP.

GRPs as a measure has some limitations. People like to think of it as a measure of impact, but that is really overstated. Impact should measure sales; this measures exposures, which is in fact assumed not actual exposures.

  • Basics of TAM (television advertising measurement):

Universe: Universe is the total or actual number of people in a defined target audience.

Reach: Reach is the number of individuals from the universe who are exposed to the medium or vehicle.

Reach is normally expressed in terms of % (percentages)

  • Calculation of reach:

If universe is: 1,000,000 individuals (it's approx. data, it's usually defined through sampling through people-meter):

For a single episode of a program (30 minutes or 1 hour) If out of above 1,000,000 of individuals 600,000 saw at least 1 minute of programme then:

Reach = (600,000/1,000,000) x 100

Reach = 60%

Variations of the reach concept:

Gross reach

Gross reach is the summation of all audiences who have been exposed to the vehicle.

  • Week 1: 1,000
  • Week 2: 2,000
  • Week 3: 1,500
  • Week 4: 1,200
  • Hence, gross reach = week 1 + Week 2 + Week 3 + Week 4
  • Gross reach = 5,700
Cumulative reach

Cumulative reach: The audiences accumulate over the time

  • The number of individuals within the TG who are exposed to the medium or vehicle over a certain period of time
  • Total time = Total average minutes (universe) x Universe
  • Total time/reach = Avg minutes viewers
  • Net reach
  • Net reach: Net reach is the summation of all audiences who have been exposed to the vehicle and excludes the duplication of the viewership.
Weeks Gross reach Total reach Duplication Total duplication Net reach
Week 1 1,000 1,000 -- -- 1,000
Week 2 2,000 3,000 (300) (300) 2,700
Week 3 1,500 4,500 (900) (1,200) 3,300
Week 4 1,200 5,700 (1,000) (2,200) 3,500
  • What is a TVR (television rating point):

TVR = Reach x Time spent

TVR = (minutes viewed/minutes available) + (minutes viewed / minutes available)/N X100

N = Number of individuals

  • Gross rating points (GRPs)

The sum of all ratings achieved in a campaign GRP levels are generally measured and reported on a 4 week basis It is a measure of the media plan's trust

  • CPRP

Measurement used in planning a television media buy based on the cost of a commercial time slot and the rating of the program where the time slot is positioned. If, for example, the cost of a commercial time slot during prime time was $1000 and the program rating for that time was 10 (which means that 10% of the total potential audience was tuned to that program), then the cost per GRP would be $1000 divided by 10%, or $100. The CPGRP measurement is a way of measuring the efficiency of media cost, as compared to measuring the cost per thousand (CPT) and is generally used when making comparisons of the various broadcast vehicles. When the actual buy is made, the advertiser will still want to know the cost of reaching people on a cost-per-thousand basis.

Programme name Time Secondages Effective rate Total amt TVR GRP
A 10:00 am - 11:00 am 150 6,000 90,000 5.4 81
B 21:00 - 22:00 200 30,000 600,000 9.8 196
Total - 350 - 69,0000 - 277

CPRP = 2,491 (i.e., Total amt/Total GRPs)

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