Glossary
What is eCPM?
Also called: effective CPM
eCPM (effective CPM) is what you actually earned per 1,000 impressions: revenue ÷ impressions × 1,000, across every buyer.
हिंदी में पढ़ेंeCPM means effective CPM. Where CPM is the price a buyer bid, eCPM is the result: total revenue divided by impressions, multiplied by 1,000. Because it works whatever the pricing model, eCPM lets you compare demand sources, ad units or days on one scale.
The denominator matters. Google Ad Manager reports eCPM per impression, but also per ad request and per matched request. An eCPM per ad request is lower, because it spreads the same revenue over requests that never filled. Always check which version a report shows before comparing.
eCPM can rise while revenue falls, for example when a higher floor sells fewer impressions at better prices. Read eCPM together with impressions or fill rate before deciding a change worked. For the earnings of your traffic as a whole, page RPM is the better guide, because it also reflects how many ads each page shows and how many fill.
Example
An ad unit earns $360 from 180,000 impressions. Its eCPM is $360 ÷ 180,000 × 1,000 = $2.00.
Why it matters to publishers
eCPM is the fairest way to compare what different partners and placements really pay you, as long as you also watch volume.