Well, just at a glance, you have your benefits copy all screwed up. If you want them to post more, put "post topics" and "talk to other members" (don't say communicate... it's too formal/businesslike) at the top and "view sexy females" lower on the list. Why do you think they're bypassing your forum?

You could invent a few names and talk to yourself to keep the convo going during dead times. Or go join some other forums with big mouth, opinionated people, and create a duststorm. Flog your website in your sig line somehow without being obvious. That's how the poets do it.
So what's your thing about anyway? Kind of looks like the Y + Politics + Sex Board material all rolled into one.