StumbleUpon has revealed some revenue numbers for the first time via a report from Bloomberg.

One major piece of news from the the quiet social content giant is that it is now profitable. It also expects to grow revenue to $35 – 40 million in 2013.

Some other noteworthy stats:

• Nearly 40% of Stumbles are on mobile (up from 20% in 2012)
• Over 20% of revenue is from mobile
• Over 100,000 advertisers and publishers create native ads for StumbleUpon including Comedy Central, Relativity Media, Levi’s, Elle and Harper’s Bazaar

StumbleUpon launched some new mobile apps and a major desktop redesign last year. These (at least the apps) appear to be paying off. The company also laid off 30% of its staff back in January, but has since been actively hiring and adding engineers.

CEO Mark Bartels will be appearing on Bloomberg West later today (3PM PST) to talk about the company’s growth.

Image: StumbleUpon Team (StumbleUpon)