HowStuffWorks, which was founded by Professor Marshall Brain in 1998 and features an expansive online archive of articles covering science, electronics, travel and communications and general interest.
The site employs around 160 full-time staff and will retain its chief executive Jeff Arnold in the sale. It currently attracts more than 11m unique users a month, and has exclusive digital rights to more than 30,000 texts, 180,000 digital maps and 800,000 images.
Discovery is also buying a minority stake in HSW International itself.
Discovery plans to create a programme format for HowStuffWorks, which is likely to air in the US on the Discovery Channel from the summer of 2008 and will roll out globally soon after.From an online perspective Discovery's plans are to integrate an online video archive of material from its various TV channels, including Animal Planet and The Military Channel, into HowStuffWorks' portfolio.
David Zaslav, president and chief executive of Discovery Communications, said: "With HowStuffWorks, Discovery now has a solid platform for strengthening our digital businesses, leveraging our video assets to create new experiences for users, advertisers and our distribution partners, and taking those opportunities around the globe."
Arnold said: "Integrating engaging clips drawn from Discovery's vast video library of more than 100,000 hours of programming with the written articles on HowStuffWorks will ultimately deliver an accurate video Wikipedia."
This article was first published on brandrepublic.com