Hey man, one door closes another one opens. get him to run a drink special. I always attempt to negotiate drink specials when i negotiate gigs. I'd rather get a bar to a $600 ring with 40 people spending $15 than 20 people spending $30.
I have found that beer specials alone don't entice people as much as a decent drink special, something bread and butter like a whiskey or rum drink is what i shoot for. I avoid seeking well-drink specials if the bar uses shit wells like Aristocrat, which only hurts my singers with hangovers. I shoot for an app special too, wings are always a good bet.
My rationale is the more I've got to promote with the better odds I have of getting singers to try out a new venue or different night. Good luck!