Media & Publishing / Audience
Reach & Frequency (Gross Rating Points) GRP (aka TRP = target rating points; R&F = reach and frequency)
How much of the audience a campaign reached and how many times each person saw it, combined into a single "weight" number.
The fork, why two teams get different numbers
GRP intentionally DOUBLE-COUNTS: it is reach × frequency, so 50% reach seen 4 times = 200 GRPs, and the same 200 GRPs could be 80% reach × 2.5 frequency, very different campaigns with identical GRPs.
In the Metric Library
- The full fork, both definitions worked all the way through
- The trap that makes the number lie, on a real export
- Every formula variant, spelled out
- The reconciliation anchor, what to tie it to and when to refuse
Reference: MRC-accredited audience measurement e.g. Nielsen/Comscore (reference); IAB cross-media reach/frequency convention (reference)