Delivery
What is CPM?
Also: Cost per mille · Cost per thousand impressions
CPM (cost per mille) is the cost to serve one thousand impressions of your ad.
CPM = (ad spend / impressions) x 1000
CPM is the price of attention in the auction. Rising CPM with flat performance usually means more competition or narrower delivery; falling CPM can signal fresh creative or broader targeting. It is a diagnostic, not a goal: cheap impressions that do not convert are not a win.
Last reviewed 2026-09-19
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