For all the differences among them, the juggernauts of social media rely on a common business model: create free services, then sell ads against users' information. In a dramatic departure, a new social network plans to give its users a 50 percent commission—or even let them sell their own ads and keep all the revenue.

Chime.in is built around users' interests—think photography, politics, or travel—as opposed to friends, professional contacts, or news. The site's founders hope that by creating pages around those interests, the users will attract people with similar affinities, an attractive combination for targeted advertising.

"Because social is going to be so powerful, I feel that the people who are creating the engaging social content should have some stake," says Bill Gross, the serial entrepreneur who is the CEO of both Idealab, a startup incubator, and Ubermedia, a social media developer that launched Chime.in. "Right now that's sort of a heresy—but I almost like it that people think it's heresy. It gives me more of a lead." 

Gross is no stranger to creating disruptive business models. The pay-per-click concept for advertising in search listings was born in 1998 at his startup Goto.com, a search engine that was later renamed Overture and sold to Yahoo in 2003 for $1.6 billion. "It took five years [to go from calling Overture] heresy to 'We want to own it,' " Gross recalls.

Chime.in launched last month in beta; the site will officially launch at the end of this year, with the advertising model kicking into gear in 2012.

In terms of technology, Chime.in is a highly derivative platform. It most resembles Facebook, with a string of posts and comments beneath them. Like Twitter, the content is public by default, and users can follow anyone (no friending required), but posts can be longer: 2,000 characters. Users can vote on content, much as they do on Digg. 

But the emphasis is on users' interests; after joining already existing groups or creating their own, users can sort content by those interests. Chime.in says the site is now home to 5,000 interest-based groups that have so far shared more than 25 million "chimes."