Not a surprise, but interesting nonetheless. The acquisition beefs up Discovery‘s online presence; this is the biggest digital deal the non-fiction video power has made since 2007, when it paid about $250M for HowStuffWorks.com. The companies don’t say how much Discovery paid for Revision3, although I hear it’s around $30M. Here’s the announcement:

(Silver Spring, Md.) – Discovery Communications announced today that it has entered into an agreement to acquire San Francisco-based digital video provider Revision3. Leveraging Revision3’s vast experience in creating engaging online video content in a cost-effective manner, the transaction helps fuel Discovery’s strategy of being the number one nonfiction media company on all screens.

“Discovery’s mission to ignite viewers’ curiosity and its history of pioneering new platforms – from cable to HD to 3D – make it the logical leader in this explosive new wave of digital video growth,” said JB Perrette, Chief Digital Officer, Discovery Communications, who made today’s announcement. “With Revision3’s industry-leading management team and roster of great talent, we look forward to cultivating more original content and fresh personalities that resonate with passionate communities online and across all platforms, while enhancing our innovative marketing solutions for advertising partners.”

The leading independent Internet digital video production company, with more than 23 million monthly unique viewers across 27 digital channels, Revision3 has created a technology and distribution platform that powers the scalable production, monetization and distribution of video content for passionate online communities. With programs hosted by authentic online celebrities, including top bloggers, Twitter stars and YouTube sensations, the company’s content aligns with many of Discovery’s top linear program genres, such as tech, cooking and popular science. Revision3 boasts one of the 10 largest networks on YouTube and distribution with more than 40 other partners including iTunes, Google, AOL, Yahoo!, TiVo, Roku, Boxee, CNET and Zune.

“Revision3 has always focused on creating compelling programs featuring authentic hosts that sit at the center of engaged and targeted communities,” said Jim Louderback, CEO of Revision3. “We’re huge fans of Discovery’s networks, and couldn’t imagine a more appropriate company to team up with to develop the future of original web-based video.”

Revision3 was founded in 2005 by Kevin Rose (Digg, TechTV), Jay Adelson (Digg, Equinix) and David Prager (TechTV). Louderback, former editor-in-chief of PC Magazine and a veteran of TechTV, joined Revision3 as CEO in 2007. Louderback and team will continue their leadership of Revision3 under the new ownership structure.

For this transaction, Discovery Communications was advised by Paul, Weiss, Rifkind, Wharton & Garrison LLP, and Revison3 was advised by RBC Capital Markets and Gunderson Dettmer Stough Villeneuve Franklin & Hachigian, LLP.

The acquisition is subject to customary closing conditions, and the parties expect the closing to occur on or before June 1.