Online marketers should tread lightly on user-generated video and social media sites, according to the consensus coming out of last week's Ad:Tech New York conference and the Web 2.0 Summit in San Francisco, writes ClickZ.

With online content rapidly expanding, marketers are looking for new opportunities to push their own content online and create bonds between their brands and consumers. To be successful in making that connection, marketers will need to relinquish some control to consumers. Sarah Fay, president of agency group Isobar, urges companies to let their consumers tell the brand's story, since those consumers already have so much influence.

Other speakers from Ad:Tech and the Web 2.0 Summit agree that marketers jumping into sites like YouTube and MySpace must find a way to integrate their content without being intrusive or disruptive. But with U.S. online video ad spending expected to grow 89 percent next year, marketers are sure to seize any opportunity to get cozy with video and social-media sites.