I was also thinking that a good way to generate some revenue would be to sell custom graphics.
$1 for an avatar with your name on it
$5 for custom signatures
By "custom" I mean simply adding the users name. You could have 10 or so unique "premium" graphics users could choose from, and then slap their name on it and sell it for a small price.
You could use a site like https://gumroad.com which makes the transaction process simple and easy.
You could also team up with CK and Universal Draft guys to create a Premium Draft Guide that you could sell and then split the profits. I know people would pay for things like that.