Ev Williams, co-founder of Twitter, is finally getting comfortable talking about the micro-blogging company’s business models.

As little as a year ago, Williams couldn’t answer questions about how the service, which has more than 100 million users, would make money.

Now, the company is having success with advertising and will try out a variety of other business models as well, Williams said at the Web 2.0 Summit in San Francisco on Wednesday. The options include reselling data and pushing ad sales further.

Check out our video excerpt from Williams’ talk with conference co-host John Battelle.