I'm wondering if there could be a time limit on membership. Like, if you don't log in for a certain amount of days you lose your account or something, or if you don't log in within a certain time of joining, your account becomes deactivated. It wouldn't affect the regulars since most of us probably stay logged on all the time anyway. (You lookin' at me? ) It could be a long enough time that the occasional regulars wouldn't be affected by it, but it would get rid of the people who signed up years ago and then never returned.

I know they're just rough ideas but it's a starting point.