I find a majority of AMPS will ask for the house fee up front, (I always give the house fee to the provider and not the mamasan), and take the service fee or tip at the end of the session. (moreso, if you are a steady customer). I usually turn down proposals when they ask for all the money upfront, but it is pretty difficult to get out of a deal when they collect the fee up front and then after you agree on the level of service they ask for their tip up front. When you walk out on this arrangement you could lose .6. You will also find that when they want all the money up front you will usually get bad service. That is why they want it all up front because they know they can't provide quality service.