• by Mark Walsh  @markfwal, March 9, 2011

Recommendation engine StumbleUpon has secured $17 million in a second round of funding from Accel Partners, August Capital, DAG Ventures, First Round Capital and Sherpalo Ventures. All were prior investors in the company's initial $1.5 million round except DAG.

StumbleUpon said it plans to invest the new capital in its core discovery technology, expand to new platforms and increase staff. Although focused on adding engineering talent, it's also actively looking to hire salespeople for both its San Francisco headquarters and New York City office.

The company has followed an unusual path to its latest financing.

It was acquired in 2007 by eBay for $75 million before being sold back to its founders two years later. Since then, the company says its service -- which suggests Web sites for people to discover based on their personal interests -- has doubled its registered user base to more than 14 million.

StumbleUpon.com had about 4.5 million monthly visitors as of January, according to Web measurement firm Compete.

"With this new investment, we will make it even easier for people to find interesting and relevant content on the Web, whether they are on their desktop, mobile device or even TV," stated Garrett Camp, StumbleUpon CEO and co-founder. In extending to mobile, the company has surpassed 1 million installs of its iPhone and Android applications since launching them in August 2010.

StumbleUpon positions itself as a personalized alternative to traditional search engines by directing users to Web pages based on their ratings of sites and the opinions of like-minded people using the service.

Advertisers can run campaigns on StumbleUpon targeting different audiences based on their interests with paid and organic content placed on the service. Some 60,000 marketers have advertised on the site to date, according to the company. StumbleUpon has not disclosed revenues.