eMarketer has announced that ad spending on social networks will hit $2.15 billion by 2010.

The research company predicts that News Corp.'s MySpace will dominate the social networks and account for 60 percent of total U.S. online social network ad spending in 2007.

Earlier this week MySpace announced it has licensed technology from Gracenote to filter out unauthorized copyrighted music posted on MySpace member pages.

"While many marketers are rushing to experiment with social networks, in order for serious ad dollars to continue, adequate measures of return on investment need to be in place, says Debra Williamson, eMarketer senior analyst and author of the report.

"The longer existing social networks take to develop adequate ROI metrics, the bigger the opening for a next generation of networks that are built from the ground up to accommodate advertising," adds Williamson.

For a more deeper analysis on interactive marketing and social networks, read "Advertising & Social Networks-- MySpace, LinkedIn & Beyond" by Kibibi Springs.