The social networking audience is growing rapidly. eMarketer estimates that in 2008 nearly 80 million people, 41% of the US Internet user population, visited social network sites at least once a month, an 11% increase from 2007. By 2013, an estimated 52% of Internet users will be regular social network visitors.

?The steady stream of social network updates and news is now a weekly - or even daily - habit for many online users,? says Debra Aho Williamson, eMarketer senior analyst and author of the new report, Social Networks: Five Consumer Trends for 2009. ?That stickiness is good news for social networks.?

Good news because social networks have yet to develop viable revenue models. But there is still time.

Get the full story at eMarketer