What's in a clan?

I play GTA4 online with a buddy of mine and where I'm pretty dang good, he's frickin' awesome and he gets a ton of invites for joining clans. Both he and I share a similar view on gaming where as we like to be independant contractors within the game. But he asked me a question I could not answer. He asked me what was the big deal about joining clans.

I didn't have any good answers so I thought I would open it up to the gaming brain trust that is the Gamespot forums. What are the pros and cons of being in a clan?

Pros: part of a team. makes you feel like you're fighting for a cause and don't want to let your teammates down. get to know people better on your clan.

Cons: may be demanding. they want you to spend a lot of time playing.