“Your wish is my command”
If you want to let your members stay active at your forums, this has to be your motto. People have so many wishes, and you have to grant them all; well not all, but definately a lot of them.
A lot of forums’ visitors are alike: you give them one finger, and they’ll take your whole hand. That can be very disturbing for you and other members, so watch your feet when you walk the path of satisfying your members. I’ve experienced it myself when I gave too many members a moderator and administrator function. They began to misbehave, abusing their new powers as admin or ‘mod’.
You have to look out for a few things when listening to the wish of your members:
1) Is it a general wish, where almost 100% of all members agree?
2) Is there no big personal gain attached to it?
3) Will new members, and visitors agree with the changes when they’re thinking of registering as a new member?
4) Will it not stand between you and your goals?
5) Will it not stand between you and things that you planned/will plan in the future?
If you follow these little lines of reason, you almost can't make a mistake when listening to your members’ wishes.
Here are some ways to discover these wishes and will get more members active, and more visitors to register:
A feedback form or forum: If you have a feedback forum, people can ask questions about the site itself, and comment your design, coding, rules etcetera. Though if you use a feedback form that mails comments to the admin itself, post a thread about it, with a link to the right page. People will feel like you will give more attention to their opinion. You can also achieve this by posting comments on members’ feedback in the forums.
A wishlist: This is a single thread, or a custom page where people can ask for anything for the forums, within 1 line of text. There are some hacks available for vB, phpBB and some other boards. Otherwise put it in a thread, and update the first post with all suggested things once in a little while.
Polls: This brings more interactivity to your site, and also gets members to let you know their opinion. After that, people can discuss it in the forums, probably forming one absolute answer to the question asked. If you come with an idea, make a poll of how people think about it, the neccesity, originality and popularity.
Listening to your members is one of the greatests way’s to promote activity, and in a long term you might obtain more members.
Just look at it in this way: You give your members what they want, people will get more attached to your forum, people will praise your forum at other places and introduce it to friends. They become members, and they experience your great forum too. That will even make a positive vicious circle if you do it right.