help with promotion organization
 

Ok,
So i got a few sets of nice teen/amatuer content that i really dont' need. What i do need is for my webmaster board (see sig) to get popular. So i am trying to organize a promotion where someone will win the content....but i'm not sure what to do.
I wanted to see who could refer the most members in a certain date range...or i was going to make the 400th post win it....or some other ideas.
If you can think of anything else before i do, please let me know. Remember....i'm leaning towards new members.
peace