I am assuming that you are referring to your receptionists.....or employees that handle the phone calls, and clients are asking for appointments with the people who are renting from you...........I think if your employees are doing so, then the renters should pay them an hourly rate on top of their rent. In way the receptionist are employed by you and the renters, so they should make a wage by both "employers". Or raise the rent. I don't think it's fair, for your employees to work for the renters for nothing though.
I wish NJ had booth renting, it seems hairdressers can make more money that way. Here in NJ, the standard pay is 50/50 commission. 60/40 if your lucky. I am currently assisting for a stylist who has a 3,500-4,000 book every week, and he keeps 70% and pays the owner 30%. I read an earlier post that 150-200 a week is a fair price to pay rent. I wish! Receptionists make 8-12 an hour. Shampoo assistants make 8-10 an hour plus tips.