three things:

First - if your gigs are in your hometown - get some of your friends to come, at least occasionally and make a bit of a ruckus to get other to pay attention - or at least to clap really loudly.

Second - those type of gigs aren't the only situations like that. Take to a professor teaching Freshman Comp. some time - ask them how many in their "audience" are interested in the subject.

Not everyone thinks that prostitution is a horrible thing in all cases.

Play loud, play fast, and duck when the bottles start flying.

pax yall.