In more detail
CPM stands for cost per mille, or cost per thousand impressions. It measures how much you pay to show your ad 1,000 times, regardless of whether anyone clicks. Platforms calculate it by dividing total ad spend by impressions, then multiplying by 1,000. CPM is the standard way to compare the cost of reach across platforms and campaigns, and it is most useful for awareness goals where the aim is to be seen, not to drive immediate clicks or sales. It does not tell you anything about results past the impression, so it is usually read alongside metrics like CPC (cost per click) or CPA (cost per acquisition).
Example
If you spend 50 dollars and your ad gets 10,000 impressions, your CPM is 5 dollars (50 divided by 10,000, times 1,000). So every thousand times the ad is shown costs you 5 dollars.
FAQ