eCPM stands for Effective Cost Per thousand (Mille) impressions.
It’s used to determine your earnings per thousand impressions. First, you need to divide your earnings by your number of impressions. Then, you multiply this number by 1000 to bring it back to your eCPM.
For an example of eCPM calculation, please see:
All About Media Buying – Part 3 – Profit Calculation
For additional terminology and key performance indicators for measuring success, please see: