What is Effective Cost Per Mille (eCPM)?

A metric that measures the revenue generated per 1,000 ad impressions, regardless of the pricing model used.

Effective Cost Per Mille (eCPM) is a metric that calculates the revenue generated per 1,000 ad impressions, regardless of whether the ads are sold on a CPM, CPC, or CPA basis. For publishers, eCPM represents the effective revenue they earn per 1,000 impressions served. For advertisers, it represents the effective cost of reaching 1,000 users.

Why It Matters

eCPM is crucial for publishers to compare revenue performance across different ad networks, formats, and campaigns. It provides a standardized metric to evaluate which monetization strategies generate the highest returns. Unlike CPM which only applies to impression-based pricing, eCPM can be calculated for any pricing model, making it essential for optimization decisions.

How to Calculate

eCPM = (Total Ad Revenue ÷ Total Ad Impressions) × 1,000. For example, if you earned $50 from 25,000 impressions, your eCPM would be ($50 ÷ 25,000) × 1,000 = $2.00 eCPM.

Industry Benchmarks

Best Practices

Track eCPM by ad format, placement, and geography to identify top performers. Use ad mediation to increase competition and boost eCPM. Optimize ad placement and frequency to balance user experience with revenue. A/B test different ad formats and compare eCPM performance rather than just impressions or clicks.

Examples

A gaming app compares eCPM across networks: AdMob ($3.50), Unity Ads ($4.20), and Facebook Audience Network ($2.80), helping prioritize higher-paying demand sources. A news app tests rewarded video ($12 eCPM) vs banner ads ($1.50 eCPM) to optimize revenue per user.

Notes

eCPM varies significantly by geography (US/EU typically higher), app category (gaming often highest), and user quality (engaged users command higher eCPMs). Unlike CPM, eCPM accounts for actual revenue performance, making it more valuable for publishers focused on maximizing earnings.