Stitcher, the streaming radio and podcast platform, says it crossed the 12 million mobile app download mark and has doubled its on-demand content to more than 20,000 programs.

CEO and co-founder Noah Shanok says the company, which has gone through three institutional rounds of financing since its launch in 2008, has up to now been focused on growing content and audience, but is now building out its direct sales capabilities.

Revenue, says Shanok, has grown 75 percent year over year. He declined to be more specific, but says that Stitcher has tripled the number of content partners that are on its revenue sharing program and payouts have doubled in the last year.

Podcasting and audio programs were adopted by many media companies as another way to engage audiences, expand brand channels and, in some cases, drive new revenues. Some are still at it. Scientific American, the Wall Street Journal and Slate are among the top shows on Stitcher.

The rise of the mobile platform has caused a resurgence in podcasting popularity, says Shanok. 

It has also driven renewed interest from advertisers. Stitcher touts a professional, highly educated, higher income listening audience. Shanok says he’s exploring more "native" opportunities (translation: longer-form audio ads) in addition to Stitcher’s standard, but highly targeted ad placement capabilities.

Stitcher has also added to its roster of automobile integrations, including partnerships with BMW, Mazda, Ford, GM and Mini.