Follow-up to this post - I am now five months into being a loyal attendee of my spinning class, and I have to admit, the card system has worked (and we are into winter, when the numbers are up - but they have added classes).

I have also had a chance to evaluate the instructors with a little bit more thought, now that I have heard on this site what is good form and bad form. There was an instructor that I used to think was rather boring, but she had good music. Why did I think she was boring? Because the others would throw in all of those push-ups, etc. into their routines which I thought added variety and made time go faster, while she is a real purist, following the 'rules of the road', and I have to admit, I get the better workout from her class (according to how I feel and my heart monitor).