Social networking, better referred to as professional networking in the B2B world, is fascinating and still in its infancy. The poster child for professional networking isLinked In which harnessed the "six degrees of separation" concept in a programming tour de force that let you quickly determine how you might get introduced to someone you don't know through someone you do know.

Linked In was quickly followed by others with variant professional networking models. Jigsaw provides an online swap meet of sorts where participants trade business cards, tossing in those of no value to them, and removing others of higher value to them. Spoke Software offers a mixed model of contributed information augmented by compiled information.

Now Hoover's, partnering with a company called Visible Path, is introducing a new service called Hoover's Connect. The new service is very much in the style of Linked In, but utilizes slick technology from Visible Path that generates and evaluates business relationships by monitoring the user's email traffic patterns.Intriguingly, despite its long head start and a base of nearly 8 million members, Linked In seems to be actively searching for applications more compelling than professional introductions. It's pushed hard over the past few years to position itself as a tool for executive recruiters. It then introduced a job board component. Most recently, it's launched an intriguing referral-driven professional yellow pages product.

This evolution of the Linked In model suggests that professional networking is a tough nut to crack. There's no doubt professional relationships are highly valuable, but that may be the exact reason people don't want to routinely share them. How disposed would you be to introduce a good professional acquaintance to a near or total stranger, knowing that stranger wants to sell your friend something? Are you going to spend your valuable time vetting this stranger and his offering so you can make a referral to your friend with confidence? Probably not. And that's exactly what I heard from a number of people who tried to use Linked In for its original networking purpose: generally the intermediary party never responded, or said "yes" and then never followed-through. Automated professional referral networks still fall short in the trust department versus true personal networks.

What does all this mean for Hoover's Connect? I'm not writing it off before it even launches, and it's got some neat elements that might produce a different result than Linked In. At the same time, I wouldn't be surprised if Hoover's ultimately finds gold by mining the information value of its professional network a number of different ways from where it's starting out. There clearly seems to be power in professional networking; the challenge is finding and packaging it so that it consistently delivers value to users.