Leith,
Very solid idea. Good thinking.
It wouldn\'t hurt to place a little of the responsibility onto the venues. When every I email a venue about capcities and venue size, I always tell them that we are trying to pack the place. That the more people we get there, the more money they make. I have always gotten good positive responses when they realize that they have an oppurtunity to make more $$$$$$! Sometimes these people just need to be reminded about the money.
I guess what I am saying is, that if they see the potential to make money they will put a little effort into filling their place. When a dozen people show up and they haven\'t made money that night, it could hurt the band from playing there in the future.