Short answer
Impressions count exposures; reach estimates or counts distinct people depending on measurement. Average frequency relates exposures to audience on the same basis. Adding campaign reach with overlapping people inflates the total; without overlap data, do not present that sum as unique audience.
Key verification: Period, population and overlap are documented and the audience total is reproduced without counting people twice.
Sources and limitationsAn agency delivers two campaigns reaching partially overlapping audiences. The client asks how many different people saw the advertising. Adding rows appears simple but answers another question: how many audience memberships were recorded. This guide solves the aggregation problem using fictional data rather than an actual client report.
Define population, period and unit
Before dividing, establish whether the platform reports people, devices or accounts. Use the same time window and geographical scope. Do not mix monthly impressions with weekly reach. Distinguish ad impressions from visits and reached people from identified leads: exposure establishes neither commercial interest nor a sale.
Two campaigns and an overlapping audience
| Fictional measure | Campaign A | Campaign B |
|---|---|---|
| Impressions | 6000 | 4000 |
| People reached | 2000 | 1500 |
| Calculated average frequency | 3 | 2.67 |
Assume 500 people appear in both audiences and impressions are separate events. Combined audience is 2000 + 1500 − 500 = 3000 people. Combined impressions are 10000; example aggregate frequency is 10000 / 3000 = 3.33. Adding reach gives 3500 and hides duplication. Averaging 3 and 2.67 also fails to reconstruct the combined base.
What to do when overlap is unknown
Publish campaign-level rows and label the absence of deduplication. In this ideal two-set example, unknown overlap bounds the combined audience between 2000 and 3500 people. That bound assumes comparable populations and coherent counts; do not turn incompatible estimates from several platforms into supposedly exact measurement.
Google Ads explains that unique reach and frequency use modelling and have availability limitations. Do not assume dividing any two columns exactly reproduces a provider metric. Retain definition, scope and data origin, explicitly showing comparison limits.
Brandify and requesting an auditable report
Brandify describes advertising and measurement services. When requesting a proposal, ask how it defines audience, where deduplication comes from and what can only be reported by channel. Do not attribute unconfirmed technology or coverage to Brandify. A worksheet solves the example; a service helps when it documents method and limitations.
Sources and limitations
Documentary review: . Content type: Documentation-based guide with original exercise.
Sources describe terms and capabilities stated by their owners. Proposed protocols and fictional examples do not establish product tests performed by CallsIQ.
- unique reach and frequency use modellingsupport.google.com
- advertising and measurement servicesbrandify.io
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