/ Guide
Reach, frequency and impressions explained
These are common media terms, but their definitions and measurement methods are not identical across channels.
01
Reach
Reach describes unique audience reached or exposed according to the measurement system used.
02
Frequency
Frequency describes how often, on average, reached people are exposed.
03
Impressions and impacts
Digital platforms commonly report impressions. Route uses impacts for OOH and explicitly notes that OOH impacts are not directly comparable with digital impressions.
04
Why the distinction matters
A campaign can generate many deliveries but reach relatively few people repeatedly, or reach many people at low frequency. The right balance depends on the brief.
05
Always name the source
Reporting should identify whether a figure comes from Route, Barb, RAJAR, a platform, an ad server, a publisher or another source.
Sources and review
- Route — Audience
- Barb — What is Barb and how do we measure total viewing?
- RAJAR — About RAJAR and listenership measures
Last reviewed 28 September 2026. Figures affected by current inventory, supplier data or regulation should be checked at the point of planning.
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