Google and other search engines still send online publishers the bulk of their readers, but social media is gaining, according to research by Outbrain.

While search engines still dominate in sending the largest number of visitors to content sites (41 percent), social networks such as Facebook, Twitter, Digg, and StumbleUpon, delivered 11 percent of the traffic in the Outbrain study.

“It’s no secret that people are spending an ever-increasing amount of time on social sites like Facebook and Twitter. One of the by-products of this shift is that these same people are now relying on their networks of friends and peers to alert them to interesting news and content,” Outbrain writes.

We see similar patterns here at TechJournal South. While search engines, led by Google, deliver the most daily traffic (usually half or more), we see an increasing number of visitors coming from Facebook, Twitter, and other social networks.

News stories are the most shared, followed by entertainment and lifestyle stories. Sports ranked lowest among the verticals Outbrain examined.

One downside from the traffic coming from social networks is that visitors were much more likely to “bounce,” or leave the site after hitting the single link that brought them there. Chances are that someone hitting a link from Twitter or Facebook goes back to those sites rather than further exploring the site a link sends them to.

Online Media Daily offers some analysi.