I have been allowing my group clients to “pay as they come” as opposed to a full pre-payment for, say, a month long, three-times-a week boot camp. I only make money if they show up. I’m considering cancelling that policy altogether.
Most successful business models are based on a prepaid or scheduled payment plan this enables a business to project profits and if there is a need to do something special to meet daily/weekly/monthly/annual revenue goals. I do not allow for pay as you come at all.