Paid Advertising

eCPM — Effective Cost Per Mille

A normalized metric expressing revenue or cost per 1,000 impressions regardless of the original pricing model.

Definition

Effective Cost Per Mille (eCPM) is a standardized metric that converts any ad pricing model — whether CPC, CPA, CPV, or flat-rate — into a comparable cost-per-1,000-impressions figure. Publishers use eCPM to compare revenue across ad units with different pricing models. Advertisers use it to benchmark campaign efficiency across channels where they may be buying on different models. A high eCPM for a publisher means their inventory is valued highly; for an advertiser it means they are paying a premium.

Formula

eCPM = (Total Revenue or Spend ÷ Total Impressions) × 1,000

Divide total earnings or spend by total impressions, then multiply by 1,000.

Example

A publisher runs a CPC campaign that earns $150 from 300,000 impressions. eCPM = ($150 ÷ 300,000) × 1,000 = $0.50. Compare this to a CPM campaign paying $2.00 — the CPM deal pays more per impression.

Key Points

eCPM allows apples-to-apples comparison between campaigns on different pricing models
Publishers use eCPM to optimize ad unit placement and fill strategy
eCPM is not the same as CPM — it is a derived metric, not a directly negotiated price
A rising eCPM indicates improving monetization efficiency