Cost Per Thousand (CPM)

Cost Per Thousand (Mille) Impressions. The amount an advertiser pays per 1,000 ad impressions.

This pricing model typically applies to Social and Display ads where the impression itself generates the cost, and the click does not have an associated cost. For CPM advertising, the CPC is more accurately an eCPC (effective CPC) calculated as the total cost of impressions divided by the number of clicks. As the cost is incurred by the impression itself, that means that a higher click-through rate (CTR) will directly lower the eCPC.