The increasing popularity of online-dating sites and social-networking sites such as MySpace.com and Facebook.com has marketers eager to tap into the new advertising potential, but also weary about lack of control over the sites' content, writes eMarketer (via MediaBuyerPlanner). Viacom CEO Tom Freston is quoted as saying his company plans to begin advertising later this year in the online social networking market. He also recognizes the challenges of the segment.

"It's a difficult business to maintain your vitality in. (But) that's not to say it can't be done. Everyone wants to know how you're going to monetize it. You're asking people to advertise between conversations between two people," Freston says. The consumer-contribution aspect of the social networking sites gives marketers and advertisers no control over the content.

Pointing to the future of user-advertiser relationships on social networking sites, websites such as Flickr and Eurekster have started to give users a cut of advertising revenue from ads posted on their pages.