eCPM for in-app ads: how to calculate it

The numerator is ad revenue: the sum of rc_ads_ad_revenue events, converted to US dollars at each event's date. The denominator is impressions: the count of rc_ads_ad_displayed events. RevenueDot divides the two totals for the period and multiplies by 1,000. The table also shows Ad Revenue and Impressions, which are not plotted.

eCPM needs both event types. Your SDK ad tracking sends them to RevenueDot's /v1/events endpoint, from an ad network adapter or by manual capture. A network that sends revenue events but no displayed events gives a blank eCPM here, because there are no impressions to divide by.

A week or a month is the ratio of that period's totals, not the average of daily eCPMs, so busy days weigh more. Sandbox events are excluded. Filter or segment by app, country, platform and app version.

Find it in the dashboard under Analytics > Charts, or call GET /v2/projects/{project_id}/charts/ad_rpm. That is the API name of the eCPM chart. The response has the same shape as RevenueCat's Charts API.

Illustrative numbers for one day.

eCPM = 12.50 ÷ 5,000 × 1,000 = $2.50.

eCPM is the price you get for your ad space. When ad revenue changes, eCPM tells you whether the price moved or only the volume did. That separates a demand or network change from a change in how many ads your app shows.

Use it to compare countries, platforms and app versions, and to judge a change of network, ad format or placement. Read it with Fill Rate: a high eCPM does not help when most requests get no ad.

How to read it

• A blended eCPM hides differences. Segment by country and platform before you draw a conclusion.
• Weekly and monthly eCPM is total revenue over total impressions, so a few high-traffic days dominate it.
• A blank eCPM means no displayed events in that period. Check that the SDK sends them.
• The chart sums revenue the SDK reported. Networks report some revenue as estimates, so it can differ from their final reports.
• A falling eCPM with rising impressions can mean you added low-value placements. Compare with Ad Revenue.