What is behavior advertising?

The practice of behavioral advertising - the collection and aggregation of consumers' Web browsing activities for the purpose of serving them targeted advertisements. In the past, data was collected through cookies and was aggregated by advertising networks that collect user data across many different sites. Recently, advertisers have been experimenting with new mechanisms, such as deep packet inspection (DPI), to develop more detailed user profiles. Behavioral advertising presents significant privacy risks in large part because consumers are unaware of the practice and thus cannot protect themselves.