Reach & Frequency
Part of Reach and frequency planning
Reach versus impressions in a media plan
Understand how reach differs from impressions, calculate average frequency and check the definitions behind a media proposal.
Reach estimates how many people were served an ad at least once under a stated method. Impressions count ad deliveries, including repeat deliveries.
A media plan needs both: impressions describe delivery volume; reach describes how widely that volume may be distributed.
Read the figures together
A purely hypothetical plan counts 12,000 impressions and estimates 4,000 reached people for the same audience and period. Dividing the matching impression count by reach gives an average of three impressions per reached person.
That average does not mean everyone received three: some may have received one and others many more. The figures say nothing by themselves about attention or response.
In a hypothetical eligible population of 10,000 people, 4,000 reached people would be 40% reach. Without a defensible population denominator, report the count rather than manufacture a percentage.
| Figure | Question to ask |
|---|---|
| Impressions | What counted event, placements and dates does this cover? |
| Unique reach | Are people estimated, or are accounts, devices or households counted? |
| Reach percentage | Which population supplies the denominator? |
| Average frequency | Do the impression and reach figures cover the same people and period? |
| 2+ reach | How many people met the two-exposure threshold in that period? |
Use the difference to assess a proposal
Given comparable methods and similar impression totals, a plan with higher estimated reach spreads its impressions across more distinct people. A lower-reach plan concentrates them among fewer people.
Broad introduction may favour the first pattern; a task requiring repeated contact may justify the second. Neither metric is a quality score on its own.
Ask the supplier what frequency distribution, if any, is available. Do not infer a missing distribution from its average.
Keep supplier measures within their limits
An impression is a counted ad delivery, but suppliers may use different counting rules or units. Reach may also be estimated or counted in different ways. Check that impressions and estimated people cover the same audience before calculating frequency.
A forecast can differ from delivered activity. At review, compare the approved forecast with delivered impressions, available reach, the period and the settings that actually ran. State any counting differences before concluding that the plan contacted more or fewer people than expected.
