An Experian Hitwise survey of time spent online says Americans spend 27 percent of their time online using social media. By contrast, they spent 4 percent of their time on news and "adult" content.

But note: The survey "doesn’t include mobile visits made on 3G or 4G networks or app visits," Experian's James Murray writes (though another study published last year found similar results). Social use declined slightly from Experian's 2011 survey, and news use went up a little bit. Time spent on email -- hallelujah -- declined. Last fall, Pew found that one-third of adults under 30 now get their news on social networks.

The study doesn't include data on mobile, where people are increasingly getting their news. BuzzFeed Chairman Kenneth Lerer said Wednesday that mobile devices account for 65 percent of BuzzFeed's traffic.

Related: What the world population is doing on smartphones and social networks | Even on smartphones, your news is more likely to be found through social media