Cost Per Mille
The cost per thousand impressions, a standard pricing model for display and video advertising.
What Cost Per Mille means
Cost per mille (CPM), or cost per thousand impressions, is the price an advertiser pays for one thousand ad impressions. CPM is the standard buying model for brand awareness campaigns, display advertising, and video ads. Factors affecting CPM include audience targeting specificity, time of year (Q4 holiday season typically has higher CPMs), ad format, placement, and competition. From a compliance perspective, CPM-based campaigns can be impacted by impression fraud — bots generating fake impressions that inflate costs without delivering real audience exposure. Brand safety issues also affect CPM value, as impressions alongside inappropriate content may have negative brand impact. Viewability standards (e.g., MRC standard of 50% of pixels visible for 1 second) help ensure CPM-based buying delivers actual value.
Related terms
Impressions
The number of times an ad is displayed on a screen, regardless of whether it was actually seen or clicked.
Cost Per Click
The amount an advertiser pays for each click on their ad in a pay-per-click advertising model.
Viewability
A metric measuring whether an ad was actually visible to a user, based on industry standards for pixels-in-view and display duration.
Ad Fraud
Fraudulent activity that manipulates ad delivery, clicks, or conversions to generate illegitimate revenue or inflate metrics.