I was talking to a person recently who expressed how when it comes to gathering up a group of people to enter into some kind of collaborative project for fun, if it requires a lot of time commitment he insists in using money as a way to semi guarantee results.
Essentially, everyone would put say $100 into a pool of funds and at the end of the event everyone would get their money back except for those who decide to dropout in a voluntarily manner. He expressed how this has worked great for him as it sorts out people who are serious and would increase the odds that they will actually follow through in an environment where people depend on each other.
When I think about it companies do it all the time. I guess the question is would people take it as an insult?