Cost per Mille (CPM)
Cost per mille is what you pay for one thousand ad impressions.
Cost per mille (CPM), also called cost per thousand, is the price you pay for 1,000 ad impressions. The formula is total spend / impressions x 1,000. CPM measures how expensive it is to reach an audience, regardless of clicks or sales, so it is the standard pricing model for awareness and reach campaigns. It is driven by competition for the same audience, ad relevance, seasonality, and platform. Rising CPMs mean it costs more to put your message in front of people, often during holidays or in crowded niches. Marketers use CPM to compare channels and to spot audience saturation. Pair it with CTR and ROAS so cheap impressions are not mistaken for results.
Examples
- Spending 500 dollars to earn 250,000 impressions gives a CPM of 2 dollars.
- Black Friday demand pushes a brand's Meta CPM from 6 to 14 dollars.
- A narrow B2B audience on LinkedIn carries a 35 dollar CPM versus 8 dollars on TikTok.