W2 Group, a Waltham, MA-based marketing firm, has received a $30 million investment from PE firm Monitor Clipper Partners to expand the three-year-old company’s social media marketing efforts. The funding will initially be used to build out two of W2’s properties, digital marketing shop Digital Influence Group and website-focused PR agency Racepoint Group. The two units’ client rosters include Sony (NYSE: SNE), AMD, AOL/Third Screen Media, HP/Neoware and eHarmony, among others. Release

-- Boston.com: Monitor Clipper’s $30 million investment is part of a $100 million commitment. Over time, W2 Group will use the additional fundings to develop and purchase companies whose work dovetails with its other digital marketing practices. Some of the areas W2 wants to move into include branded digital community building, social networking, content/Web 2.0 publishing, mobile, online research and analytics, and domain-specific services such as healthcare. W2 is currently in the process of completing investments in three unidentified tech marketing companies. It is also exploring acquisition targets for Racepoint in Tokyo and Shanghai.

W2, which is headed by Larry Weber, who sold his eponymous PR firm to Interpublic Group for $16.5 million in 1996, claims its is on course to earn about $4 million in 2007, with revenue of about $20 million.