I used to be a member until I was forced to give it up due to financial circumstances. Instead, I bought a couple of dvds and some weights. I'm just as fit if not more so.
Anway, I worked out that with my gym you have to go at least three times a week, every week, or you'd be better off paying as a casual user. I know a few people who are members of the very same gym (council run) and all but one go less than three times a week, every week. Sometimes they'll be good and go every other day and then not go for a month.
I could afford to rejoin, but I can't see the point. It's an emperors new clothes scenario in my opinion.