What is CPM, eCPM & vCPM?
Also known as: Cost per mille, Effective CPM
Quick definition
CPM is the price paid per 1,000 ad impressions; eCPM normalizes revenue from any pricing model into a per-1,000-impression figure so different demand sources can be compared; vCPM counts only viewable impressions.
How it works
- CPM = cost ÷ impressions × 1,000
- eCPM = total revenue ÷ impressions × 1,000
- vCPM = cost ÷ viewable impressions × 1,000
Key points
- Use
- Publishers rank demand by eCPM; buyers use vCPM to avoid paying for unseen ads.
Benefits
- Simple comparison across sources
Trade-offs
- Ignores outcome quality unless paired with performance metrics
FAQ
Why does eCPM differ from CPM?
eCPM includes revenue from CPC, CPA or fill-rate effects, so it reflects actual earnings per thousand impressions served.
Explore on AdTech Radar
Official sources
Last reviewed 2026-10-27. Explanations are written by AdTech Radar; consult the official specification for implementation.