Oggie's right. Having left a profit at almost all my gigs on the % basis I have happily subsidised less well known guests. I get angry though when I hear an organiser tell me that some other act has come to the club promising to do all the mail shot work to their extensive list etc only for them to turn up having done nothing because the fee is fixed and playing to a handful of people before taking all the profit I left the week or month before. And believe me it has happened a few times. Interestingly it appears to be the younger bands or artists who do this.