Many of the clubs (at least here in NYC), to save/make money, are now requiring that a performer have a minimum number of reservations or the show will be cancelled and the performer will forfeit the deposit or have to pay a minimum room charge or both. In one room the number is 30 reservation or either the show is cancelled or the performer has to pay the club a per/person fee for the difference between the number of seats filled and the minimum number.
If you intend to see a show be sure to make a reservation in advance. It can help assure that there is a show to see and will save the performer considerable expense (musicians need to be paid, show or now show, etc.)
That's CABARET ETIQUETTE!
WISHING YOU A BLESSED AND PROSPEROUS NEW YEAR!
HUGS
STU