Cost per impression

Cost per impression vs CPM — same math, different reporting labels.

MetricsCross-platform

Cost per impression is spend divided by impressions — mathematically equivalent to CPM ÷ 1,000 when both use the same impression definition. Operators usually say CPM for awareness buys and “cost per impression” when reconciling billing lines or non-standard inventory.

Synonym confusion with CPM is common; always check whether the report uses 1,000-impression units.

Sources

IAB Glossary →

Related terms

Cost per mille (CPM)
Impressions
Frequency

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