Potential revenue stream for the site that is fairly noninvasive.
viglink.com

This fun little toy turns all the links that people post on the site into affiliate links.  You have the option to back off how aggressive it is at converting links. (I had to back mine off a little)

I have yet to be payed by the company, but It does seem to be working.  It only converts on actual sales so I believe they will probably pay.  This site basically operates like mine and you let people post links to anyplace they want.  You might as well get a small cut since you are advertizing for those companies.

The link I posted is a referral link.  You can bypass me if you want, but I am telling you how to make a little free money.