Revenue-sharing ad network Adjix launched an ad format that lets users embed text ads within "tweets" (Twitter posts).

When users use Adjix2Twitter to post to their Twitter accounts, a small text link appears at the end of their tweet. The linker must approve the ad before it is sent. See video demonstration.

Advertisers can set accounts up so anyone can run their ads. Conversely, ads can be limited to certain Twitter accounts. Brands can also decide how frequently an ad runs, either on an account or in given locations.

Adjix was founded in August 2008 by former Apple engineer and marketer Joe Moreno, who specifically sought a way to monetize Twitter — a company that, despite its public merits, struggles to peg down a business model.

The microblogging site launched in March 2006, but 70% of members began using it in 2008, according to HubSpot. In February 2009, over one in ten (11%) of online adults in the US said they'd used Twitter or a similar microblogging service in the past.

The company recently drew $35 million in Series C funding.

This isn't the first time others have attempted to monetize the site's model. Twitter marketing account management company HootSuite (formerly BrightKit) gives users the ability to run AdSense half-banner ads from outbound Twitter links via ow.ly, its URL shortening service. And Yammer, whose format is Twitter-inspired, charges enterprises a monthly fee for internal employee use.