Social networks made $400 mln in revenues in 2006

IDC estimates that social networks only made about $400 mln in revenues in 2006, but could make as much as $1 bln in 2007. IDC expects that most social network services will employ a mix of business models, including advertising, subscriptions, and ecommerce. Of these three models, only advertising scales well enough to make social networks interesting for portals and major media companies.