People keep citing the Booth’s small capacity as the reason for its low grosses, but I don’t think that’s the case.
First off, it’s not hitting 100% capacity each week. Meaning that, even with its small number of seats, the supply is still higher than the demand. No prospective ticket-buyer is getting shut out; 5,037 wanted to see Kimberly Akimbo last week, and that’s how many people saw it. Theoretically, it would still be 5,037 people if the show were in the Gershwin. If anything, the intimacy might be a selling point that the Gershwin wouldn’t have.
Secondly, if you look at something like Hadestown as a point of comparison; another Best Musical winner that was in a small house, and kind of off-beat (not the sort of show that tourists would automatically flock to without a Best Musical win and strong word of mouth). After their Tony win, Hadestown was making 2-3 times the money than Kimberly is making, in a house that’s only about 200 seats larger.