The Little Web 2.1 Handbook - Chapter 1


See TechCrunch:

"[...]Just look at Facebook’s Vanity URLs for proof: Facebook made it very clear that these are permanent, which means that you’re going to be stuck with the same username five or ten years down the line. Yet there are still countless users grabbing names like ‘drunkdude’. That’s going to look great when your boss tries to add you as a friend.[...]"