What is eCPM?
eCPM (Effective Cost Per Mille) represents the revenue earned by a publisher for every 1,000 ad impressions served. "Mille" is Latin for thousand. Unlike CPM (which is the price advertisers pay), eCPM normalizes revenue across different pricing models (CPC, CPI, CPA) into a comparable metric.
eCPM Formula
Example: $500 earnings ÷ 250,000 impressions × 1,000 = $2.00 eCPM
Why eCPM Matters for Publishers
eCPM is the universal language of ad monetization. It allows publishers to:
📊 Compare Ad Networks
Evaluate which networks deliver the highest revenue regardless of their pricing model.
🎯 Optimize Placements
Identify which ad placements and formats generate the most revenue per impression.
💰 Forecast Revenue
Project future earnings based on expected traffic and historical eCPM rates.
🔄 Set Floor Prices
Establish minimum eCPM thresholds for waterfall or bidding setups.
eCPM Benchmarks by Ad Format
| Ad Format | iOS eCPM | Android eCPM |
|---|---|---|
| Rewarded Video | $15-30 | $8-18 |
| Interstitial Video | $10-20 | $5-12 |
| Interstitial Static | $5-10 | $3-6 |
| Banner (320x50) | $0.50-2 | $0.20-1 |
| Native Ads | $3-8 | $2-5 |
Factors Affecting eCPM
Geography: Tier-1 countries (US, UK, Germany) command eCPMs 5-10x higher than Tier-3 markets.
Ad Format: Video and rewarded formats significantly outperform static banners.
User Quality: Engaged users with purchase history attract higher advertiser bids.
Seasonality: Q4 typically sees 20-40% higher eCPMs due to holiday advertising budgets.
Fill Rate: Higher fill rates generally mean accepting lower-paying ads, potentially reducing eCPM.