A new study has found that more than half of social network users believe their experience would be better if marketers offered targeted ads.

The study, by Prospectiv of Woburn, Mass., found that 56 percent of the 800 participants said their time spent on social network sites would be better with brand targeting. About 54 percent said they never respond to ads on social networks, while 87 percent said the ads seldom or never match their interests.

MySpace and Facebook, the two leading social networks in the U.S., have been criticized as unworthy ad platforms and have fallen into hot water with privacy issues as they try to move into targeting. Facebook's Beacon snafu made headlines by not informing users of their participation, and while some have called the company clueless when it comes to targeting, Facebook still sees BT as the way of the future.

"The perception is that advertising is a cost that users pay to experience a free site. But the more that we can do to reduce that perceived cost, by providing targeted and relevant advertising, the better," Mike Murphy, Facebook's VP of media sales, told BrandWeek.

Meanwhile, MySpace is in the midst of launching HyperTargeting, a program that allows advertisers to message users based on their interests.