Definition of eCPM in online advertising

eCPM is effective cost per thousand advertising impressions in online advertising. Mille is the latin word for thousand.

While CPM is the actual price (per thousand ad impressions) when buying ad impressions, eCPM is a calculated metric that tells you what the CPM would have been if you bought ad impressions instead of clicks, actions etc.

The term CPM is often used instead of eCPM in the everyday language.

In this case it is actually an eCPM of 10 USD, not a CPM:
- When I was going through the reports for our last CPC campaign I realized that it gave a CPM of 10 USD.

See also the definition of CPM and the article about buying methods in online advertising.

I also recommended using the CPM calculator to make sure you get your numbers right.