These are just some ideas, which may have already been considered, but I'll suggest them anyway.
1. Create a "Members Only" section, which will encourage people to post and reach Member status. Have a "Fasttrack" option, which means they can pay $50, or whatever, to become a member right away. This section could be where we discuss more private special deals or information, to keep the riffraff and search engines from seeing.
2. Have quarterly or monthly "Referral Contests" with a 100 points, or similar, reward. The points could be used toward paid IMT Tools or other services.
3. Offer services like Namepros.com's NP$ Store section. Take a look, you'll see what I mean.
4. Create a section where it requires a large number of posts, several Thanks, and a reasonable one-time fee. This section would be for veteran, core members of IMT. This section could be like the "War Room" of WF, but even more private and special.
That's all I could think of right now. I'd love to hear some feedback.