CPM (Cost Per 1,000 Impressions)
Stands for "Cost Per 1,000 Impressions," and is used in online advertising. CPM defines the average amount of revenue a web publisher receives for every 1,000 impressions on his website. An impression is counted each time an advertisement is shown. While some advertisers pay publishers an amount based strictly on impressions, most advertisers pay for individual clicks or leads generated from their advertisements. Therefore, CPM is typically an average of the revenue generated from clicks or leads for every 1,000 ads shown.
Web publishers use CPM as a way of measuring how effective advertisements are at generating revenue. If certain advertisements generate a low CPM, publishers will likely switch to different ads that provide higher CPM rates and higher revenue. The CPM model is not only found in online advertising, but is used in several other types of advertising mediums as well.