Boomerang uses personal profiles to link advertisers with their target audience.
It compiles user profiles from cookies, online sales, and information users provide at member sites. The service uses a cookie to assign each user a number, but the advertiser is never told the actual identity of the user. When a user identified by Boomerang visits a member site, the profile information lets an advertiser target that user. For instance, said David Rosenblatt, director of Closed Loop marketing at DoubleClick, a user identified as a jazz lover would see a banner ad by a company selling jazz CDs once he or she clicked on a member site. But the technology doesn't track user behavior, Rosenblatt said, it only recognizes them.