What is eCPM (Effective CPM)?

eCPM (Effective CPM) is effective cost or revenue per thousand impressions accounting for actual clicks and conversions—not only the nominal CPM in the deal.

Formulas

• Publisher eCPM = (Revenue ÷ Impressions) × 1000.
• Buyer eCPM = (Ad spend ÷ Impressions) × 1000—equals CPM under pure CPM billing.
• Performance eCPM = (Offer revenue ÷ Impressions) × 1000.

Why buyers use it

Compare placements and creatives with different CTR on a common impression base. CPM $2 at 1% CTR can beat CPM $1 at 0.2% on revenue eCPM.

Do not confuse

eCPM ≠ EPC. EPC is per click; eCPM is per thousand impressions. In mobile mediation, eCPM is the core app inventory monetization metric.

See also: CPM, EPC, programmatic advertising, display ads.