Cost per mille, often abbreviated to CPM, means that advertisers pay for every thousand displays of their message to potential customers (mille is the Latin word for thousand). In the online context, ad displays are usually called "impressions." Definitions of an "impression" vary among publishers, and some impressions may not be charged because they don't represent a new exposure to an actual customer. Advertisers can use technologies such as web bugs to verify if an impression is actually delivered.:59
Who created the 7 Cs of communication
As advertisers collect data across multiple external websites about a user's online activity, they can create a detailed profile of the user's interests to deliver even more targeted advertising. This aggregation of data is called behavioral targeting. Advertisers can also target their audience by using contextual to deliver display ads related to the content of the web page where the ads appear.:118 Retargeting, behavioral targeting, and contextual advertising all are designed to increase an advertiser's return on investment, or ROI, over untargeted ads.