eCPM

A metric measuring the advertising revenue generated per 1,000 ad impressions, used to evaluate ad monetization efficiency.

Effective Cost Per Mille (eCPM) is a key performance indicator used by digital publishers, mobile app developers, and internet platforms to measure the monetization efficiency of their advertising inventory. While standard CPM represents the cost an advertiser pays for 1,000 impressions under a specific contract, eCPM calculates the actual total ad revenue earned per 1,000 impressions across all buying models, including cost-per-click (CPC) and cost-per-action (CPA). To observe eCPM, a company divides its total advertising revenue earned over a specific period by the total number of ad impressions served, then multiplies the result by 1,000. This standardizes different revenue streams into a single metric, allowing management and investors to compare the performance of various ad formats, geographic regions, and user segments on an equal footing. Investors monitor eCPM trends in ad-supported businesses to assess pricing power, user engagement quality, and the effectiveness of ad-targeting algorithms. A rising eCPM indicates that a platform is successfully extracting more value from its traffic, which can drive margin expansion. Conversely, a declining eCPM may signal deteriorating advertiser demand, poor ad placement, or a shift in user demographics toward lower-value regions.

An online publisher serves 4,000,000 total ad impressions across its website and generates $12,000 in total advertising revenue from a mix of click-through and view-through campaigns. The eCPM is calculated as ($12,000 / 4,000,000) 1,000 = $3.00.