I just thought that some places the PPS/MMS would have some 'tutorial' for the girls and make sure that they serve the customers properly, otherwise they get the boot. I recall years ago when I went to a place in Shanghai that would require the client to give a feedback over the phone in the room to say if he is satisfied.
Also, I was told (didn't verify), that some places would ask if you mind having a newbie on job training. You will be served by a newbie while the oldie/instructor/senior watches by the side and corrects her if she is not doing it right.
Has anyone experienced this?