I find that offering stuff is a great way to have members come back, Choose something that will make members want to come back and be a active member of your community. What i have done, was I added free hosting to active members, on my site eDesignforums.com, On this thread,
http://edesignforums.com/showthread.php?tid=351 It shows users that, if they post, they get a hosting account from a reliable web host. By offering this service, it will encourage users to come back and post for the next months to follow
It's one method but not sure if the bang for the buck is there.
yeah I've tried something similar and no luck. depending on your site type (i own warez site) rapidleech seems to be very attractive to members. I'm making it available to uploaders for my site and you'd be amazed how many people are willing to actively upload if they have access to rapid-leech.
Free guides are always the best outlet. Guides that you don't intend to sell and are only available on your forums.
RS / MU / HF(hotfile) premium accounts given to the members via some weekly / monthly competition would also attract more users !
