In reply to Jeff Chandler.

I do think he makes one good point. Maybe there are people who can afford to spend many hours doing purely volunteer work only because they enjoy it, with no thought whatsoever of any benefit to their business or career -- but most of us can't. The most successful online community I've been part of struck a great balance with this: everybody enjoyed the community and learning and camaraderie, but once you had a reputation, that link in your signature did help you earn money. It was subtle -- you never felt like people were only there for profit -- but the profit they got indirectly made it possible for them to spend hours helping other people. Which everybody enjoyed. I don't think it's necessary for everybody who is helping out to be 100% free of any motive that it might help his or her career, as long as it's done in a low-key and respectful way. It allows a lot of people to volunteer who ordinarily just couldn't excuse spending so much time away from working for a living.