Microsoft has integrated behavioral targeting into paid search advertising via its adCenter platform.4739

As of Tuesday, advertisers have the capability of showing their pay-per-click ads to users based on their web-surfing history, reports
MediaPost. Microsoft's MSN unit will study surfers' search behavior to
deduce their interests and categorize them among 18 audience segments,
including mobile users, internet power users, gamers, movie watchers,
new/expecting moms, parents, and various categories related to travel
searchers and auto buyers.

Behavioral targeting
differentiates paid search via adCenter from market leader Google's
AdWords and Yahoo's Search Marketing. adCenter's targeting capabilities
include daypart, demographic and geographic targeting.

Behavioral Targeting ON: Comes to Microsoft’s adCenter via @jpenabickley