• by Gavin O'Malley  @mp_gavin, May 10, 2011

In preparation for its next phase of growth, social-media software company Clearspring said it secured $20 million on Tuesday.

With the new funding -- led by Institutional Venture Partners, alongside existing investors -- Clearspring is considering various acquisitions opportunities, along with other options to broaden its product portfolio.

"We've had a singular focus on making it easy for publishers to drive traffic to their sites via social sharing," Hooman Radfar, co-founder and CEO of Clearspring, said. "With this investment, we can now bring the power of that reach back to the individual publisher via our next-generation tools and services."

Founded in 2004, Clearspring has now raised a total of $60 million to expand its Web presence, while managing to redefine its core business along the way.

Currently, more than 9 million Web sites rely on Clearspring's AddThis platform, where visitors can share articles, videos and other content across their social networks.

Having accumulated loads of consumer data in the process, Clearspring has built a business connecting major brands with millions of Web Internet users in real-time.

With revenue on track to triple this year, according to Clearspring, the company says it's now hiring a new employee nearly every week, which will result in its almost doubling its staff this year.

Clearspring recently announced the integration of Audience Platform with major demand-side platforms, including WPP's Media Innovation Group, Invite Media, MediaMath, DataXu, Turn and Yahoo's Right Media Exchange.

The platform taps into the company's real-time data processing engine to aggregate influence and intent data from across the AddThis platform, which now reaches 1 billion unique users monthly.

AddThis, available on the Web and mobile, offers various marketing insights into consumers through social signals, such as Facebook "likes," interests and purchase intent.

Institutional Venture Partners joins Clearspring's roster of investors, including New Enterprise Associates, Novak Biddle Venture Partners, former AOL vice chair and president Ted Leonsis, AOL co-founder Steve Case, Capital One co-founder Nigel Morris and Silicon Valley super-angel Ron Conway.