In the spas, you have to tip. At least 20% just for the massage itself. I say at least because some of the massages aren't real massages at all. But if you get an obviously trained masseur, you gotta pay the service for what it's worth. The masseurs get $20 per 60 minute session regardless of where they are: TSMS, SMS, ShangriLa, etc. So, for a trained masseur, at least $40. The more you get on top of the massage, the higher the tip. Don't cheap out.