I have taught guild classes in the past. We don't charge a deposit, but we have been discussing asking for payment up front ($10) because members sign up and then don't show. Yes, the location is free but there is still preparation by the workshop chairman and the instructor. It's very discouraging to have 5 people sign up (our minimum) and then have 1 person attend. Even when the instructors call to confirm with students, this happens. I provide a phone number on the supply sheet and still no one calls to say they aren't coming. Our guild is close to canceling the whole program.