Cost Per Mille / Advertising Terms Cost Per Mille Cost per mille, often abbreviated as CPM, is a digital advertising metric that represents the cost of one thousand ad impressions. “Mille” is the Latin word for “thousand.” CPM is used in campaigns where the focus is on visibility and brand awareness rather than immediate clicks or conversions. Advertisers pay a set rate for every thousand times their ad is shown, regardless of whether users interact with it. CPM is commonly used in display advertising, video ads, programmatic campaigns and social media platforms such as Facebook, LinkedIn and YouTube. For example, if a campaign costs $20 and delivers 1,000 impressions, the CPM is $20. It allows marketers to compare the cost efficiency of reaching audiences across different platforms or formats. While CPM does not measure engagement, it is useful when reach, frequency and exposure are the main objectives, especially in awareness or top-of-funnel campaigns. Optimising for CPM involves balancing cost with quality placements and relevant audiences. A low CPM can be attractive, but if the impressions are served to poorly targeted or disengaged users, the results may not justify the spend. Factors like ad quality, targeting settings, competition and ad format can all influence CPM rates. For nonprofits and awareness-driven campaigns, CPM helps track how efficiently a message is delivered at scale. For B2B or e-commerce brands, CPM may be part of a broader mix that includes cost per click and cost per conversion. When used strategically, CPM supports brand visibility and complements performance-based metrics.