Definition
Impressions count how many times your ads were shown (not unique people).
Example
If an ad is shown 3 times to the same person, that counts as 3 impressions.
How to use it
- Impressions = reach * frequency (approximately, within a time window).
- Use impressions with CPM to estimate spend: spend ~ impressions/1000 * CPM.
- Monitor impressions by placement to detect low-quality inventory.
Common mistakes
- Assuming impressions equal unique users (reach is the unique metric).
- Optimizing for impressions without checking CTR, CVR, or profit.
Measured as
Measure Impressions with a fixed attribution window, conversion event, and spend basis before comparing campaigns or creative tests.
Misused when
- Assuming impressions equal unique users (reach is the unique metric).
- Optimizing for impressions without checking CTR, CVR, or profit.
Operator takeaway
- Impressions = reach * frequency (approximately, within a time window).
- Use impressions with CPM to estimate spend: spend ~ impressions/1000 * CPM.
- Monitor impressions by placement to detect low-quality inventory.
- Use Impressions only inside a stable attribution rule, conversion definition, and time window so campaign comparisons stay honest.
- If performance changes, check whether the metric moved for a real business reason or because the measurement setup changed underneath you.
Next decision
- Read Frequency and creative fatigue: diagnose performance decay and fix it if the decision depends on interpretation, policy, or trade-offs beyond the raw formula.
- Decide which report owns Impressions before comparing campaigns, channels, or creative tests.
Where to use this on MetricKit
Guides
- Frequency and creative fatigue: diagnose performance decay and fix it: Learn how frequency, reach, and impressions interact with CTR/CVR, when to cap frequency, and how to refresh creatives without tanking learning.