No, because there will be preparation time inbetween clients. An SP will always make more money seeing clients who make fewer longer bookings than more short bookings because of this. For an SP her work day will comprise of three components, (1) preparation (getting ready, taking calls for bookings, etc), (2) the deed itself, and (3) cleaning up (any personal grooming, redoing the covers, tidying up etc). she only gets paid for (2) however, so the more time she can spend doing (2) and the less doing (1) and (3), the more money she will make in general, assuming that her hourly rate is approximately constant. The main motivation for doing shorter sessions IMO would be that demand for longer sessions (with her) isn't there, and she essentially needs to reduce the cost to make it more attractive to clients while still maintaining a reasonable income for herself. And the way to do that is a shorter booking but at a higher per minute cost. The downside to that is that she will probably see a different demographic of clients, which might offend her sensibilities, so there is that to consider as well.