'CPM' (Cost Per Thousand Impressions) is a pricing model in advertising where advertisers pay for every thousand impressions of their ad. It is commonly used in digital advertising campaigns to price ad visibility and reach.

CPM is an important metric for advertisers focusing on brand awareness and reach, rather than direct response or conversions. It allows for easy comparison of the cost-effectiveness of different advertising platforms and campaigns based on the number of impressions they generate.

While CPM provides an overview of reach, advertisers often complement it with other metrics like CTR and conversion rates to understand the full impact of their advertising efforts on audience engagement and actions.