When I visited the offices of LinkedIn about six months ago, the place was frenetic with activity as the business networking site was in the midst of surging growth.

Investors wanted a piece of it, naturally, and indeed today LinkedIn announced a Series D funding of $22.7 million. The investors include a mix of VCs as well as strategics: Goldman Sachs (NYSE: GS), The McGraw-Hill Companies (NYSE: MHP), SAP Ventures (NYSE: SAP) and Bessemer Venture Partners.

The deal indicates that LinkedIn's growth prospects remain intact. After all, in the current tough economic environment, business networking is critical.

LinkedIn's investor roster also shows that the company is likely to expand into new categories. For example, with the support of SAP, LinkedIn can make inroads into on-demand enterprise computing.

Dan Nye, who is the CEO of LinkedIn, wrote this in his blog:

"I'd like to reiterate our commitment to creating the right partnerships to help us build a great service for over 30 million professionals on LinkedIn today - a number that's growing by leaps and bounds each month. This funding strengthens LinkedIn further, and will help us to continue creating additional services for professionals to connect and collaborate more effectively, around the world. Services that allow you to connect with the people you trust, build out a robust online professional profile and collaborate with members of your professional network on LinkedIn."

Tom Taulli is the author of various books, including The Complete M&A Handbook and The Streetsmart Guide to Short Selling: Techniques the Pros Use to Profit in Any Market. He is also the founder of BizEquity, a valuation website.