Whilst I agree with the sentiment of no freebies on guest nights, you do need floor singers to get the ball rolling.
Many years ago I used to run the Red Lion at Patricroft, we had a guest each week and the first 5 floor spots got in free, two for the first half three for the second half. After that everyone paid even well known "names". floor spots were limited to 2 songs each, or on occasion 3 but I would cut the number of performers down, although the 5 got in free, I would normally ask a regular if they minded taking a "rest" that week
We kicked off at the stated time even if the audience was thin and within a short time word got around that this club started on time and if you wanted a floor spot you had to be there early. Phil Cusack took over the club when I left to go to college down south and continued to run a very sucessful club for a long time.
After problems (i think) witht he landlord he moved the club to the Town Hall in Eccles a venue that lacked the intimacy of the Red Lion.
Good Luck witht he club we may get across the borders some time, having moved to Yorkshire to carry out missionary work on the natives