Glossary
What is CPM?
Also called: cost per mille, cost per thousand impressions
CPM (cost per mille) is the price an advertiser pays for 1,000 ad impressions. A $2 CPM means $2 for every 1,000 impressions.
हिंदी में पढ़ेंCPM stands for cost per mille, mille being Latin for thousand. It is the standard way display and video ads are priced. Buyers bid a CPM, and floors, line item rates and Prebid price buckets are all set as CPMs, even though each auction sells a single impression.
To turn a CPM into money, divide by 1,000. A $2.40 CPM means one impression earned about $0.0024 before fees. For a whole report, revenue is CPM multiplied by impressions, divided by 1,000. The same maths works backwards: earnings divided by impressions, times 1,000, gives the effective CPM, or eCPM.
A higher CPM does not always mean more money. If a floor pushes CPM up but leaves more impressions unsold, total revenue can fall. That is why publishers watch CPM together with fill rate, and track page RPM to see what their traffic actually earns.
Example
2,400 impressions sell at a $2.00 CPM. Revenue is 2,400 × $2.00 ÷ 1,000 = $4.80.
Why it matters to publishers
CPM is the price side of your revenue. Comparing it with fill rate and RPM tells you whether a change in earnings came from price or from volume.