Behavioral targeting comprises a range of technologies and techniques used by online website publishers and advertisers aimed at increasing the effectiveness of advertising using user web-browsing behavior information. In particular, "behavioral targeting uses information collected from an individual's web-browsing behavior (e.g., the pages that they have visited or searched) to select advertisements to display"
Benefits of Behavioral Targeting
Proponents of behavioral targeting believe that it is beneficial for the user and the online property. A more targeted experience will naturally be more interesting to a user and provide an improved visitor experience. Advertisers are also able to benefit because users will be more engaged in targeted advertisements. This leads to improved click-through-rates and higher levels of interaction.
source: Anil Batra