I ran a site once with lots of community content. Moderators worked for free and were just picked from the forums. Site was able to use as much bandwidth as I could get. We even started letting people donate hosting accounts and had a mirroring script they could run to help handle the bandwidth consumption.

So anyway, in my experience, traffic was easy to get and you'd make money if your revenue was greater than your bandwidth costs. Revenue came in from ads, donations, premium memberships with access to restricted areas and status in the forums, etc.. Re ads, pay per click is low, but affiliate stuff pays a lot - getting someone to sign up for a subscription to a high quality porn site nets big $$$ and there are always some people that have plenty of money and will pay more for better quality.

So anyway, if you see any good deals on bandwidth with no adult content restriction, I say go for it! :)