Facebook has much drama that makes for good press coverage, but most of its features are worthless for a B2B site
that, say, is trying to sell forklift trucks to 50-year-old warehouse
managers. Instead of adding Facebook-like features that let users
“bite” other users and turn them into zombies, the B2B site would get
more sales by offering clear prices, good product photos, detailed
specs, convincing whitepapers, an easily navigable information architecture, and an email newsletter.

http://www.useit.com/alertbox/web-2.html