Occasionally potential guests at my club suggest a percentage of the door against a fee set by them. I don't want the hassle of working out maths on a Friday night, so this idea is immediately rejected. I do work from a low base, as it is a very small club. This low fee is always against 100% of the door. This can often pay dividends to an act that can attract a lot of people, rather than a fixed higher fee, and generally, our guests are pleasantly surprised to get an extra few squid.