Considering users can contact each other by exchanging their e-mail-address either in the forums or on their profile-pages, so they are not going to pay money to get in touch with other members via private conversation. they just exchange their Yahoo-messenger-ID or any other ID to get in touch with each other, so making money to "connect" users is not working.
Asking users to pay for "moods" or "special icons" for their profile-page, not sure whether this is really a generator of income, let alone Google-adsense where you need quite huge traffic in order to make a few dollars.
Am wondering what are the biggest or best ways to monetize a forum? Seems rather difficult from my perspective....