Long ago I used to be a regular customer at a massage therapists office and paid dues into their sort of "subscription service" program. They charged a monthly fee about equal to a 1 hour massage, but would give a substantial discount when you actually get massages -- it broke even after about 2x per month which worked well enough for me.

The incredible part was that they tracked whether you got a massage that month. If not, you'd get a 1/3rd credit for a free massage. And after 3 months of no use they would stop billing the monthly fee until you return (and collect your free massage). It was, to me, unbelievably consumer-friendly and reflected well on the business. I recommended everyone I could, and they deserved it.

Unfortunately the place shut down shortly after I moved away.