Take your local fitness club for example, that can perhaps facilitate 100 or so members at any given time, yet those clubs will often sell 1000s of memberships. Imagine if all those members showed up at one time!!! :)

Good example.

I believe there have been some proposals to keep clubs from charging a customer if they don't show up for 31 days.

If your business model relies on charging people for ZERO services, you are running a scam.