"once you have been caught a couple of times you tend to give unknown artists a miss"

But, thanks to YouTube and SoundCloud and the like, nobody ever needs to "be caught": you never need to pay to see someone you haven't heard. I can't remember the last time I went to a gig to see someone I hadn't already checked out on YouTube.

I've also found that free-entry gigs get, paradoxically, a much worse turn out than cheap, normal or even expensively priced ones. I'm sure people fully intend to turn up .... right until it actually comes to leaving the house. Then they simply can't be bothered. Generally, I think people turn up to things they want to turn up to. The trick is to convince people to actually go and listen to the performer in advance.

Or book certain acts as a support act first; then as main act 6 months or a year later.