eCPM stands for Effective Cost Per Mille, where “mille” refers to one thousand impressions. eCPM is a metric used in digital advertising to measure the average revenue generated per thousand impressions for a specific ad campaign or ad placement. It provides insights into the effectiveness and monetization potential of ad inventory. 

Why does it matter? 

eCPM is an essential metric for advertisers, publishers, and ad networks as it helps evaluate the revenue-generating capability of digital advertising campaigns and inventory. Understanding eCPM can provide valuable insights into campaign performance, pricing strategies, and revenue optimization. 


The formula to calculate eCPM is as follows: 

eCPM = (Total Earnings / Total Impressions) * 1000 

To calculate eCPM, divide the total earnings generated from an ad campaign or ad placement by the total number of impressions, then multiply the result by 1000 to normalize the value to per thousand impressions. 


Let’s consider an example to illustrate the calculation of eCPM. Suppose an ad campaign generates $500 in total earnings and receives 100,000 impressions. 

eCPM = ($500 / 100,000) * 1000 eCPM = $5 

In this example, the eCPM for the ad campaign is $5, indicating that the campaign generated an average revenue of $5 for every thousand impressions. 


A higher eCPM indicates higher revenue potential and better monetization of ad inventory. It suggests that the advertising campaign or placement is performing well in terms of generating revenue per impression. Advertisers can use eCPM to compare the performance of different campaigns or placements and optimize their ad spend accordingly. 

Publishers and ad networks can also use eCPM to evaluate the value of their ad inventory and make informed decisions about pricing, ad placements, and optimization strategies. By focusing on higher eCPM campaigns or placements, publishers can maximize their revenue potential. 

It’s important to note that eCPM is a relative metric and should be analyzed in conjunction with other performance metrics such as click-through rate (CTR), conversion rate, and return on ad spend (ROAS) to gain a comprehensive understanding of campaign effectiveness and profitability.