@ReynST I love the way you worded that. More than a decade in to hiring masseurs, I believe the tip is perhaps more for my sake than anything else in that I'm older, prefer evening massages in my home and I live in the suburbs. From the pool of 130 masseurs advertising on RM in my area, maybe 5 that I'm interested would be willing to accommodate that service, so I understand tipping well is important.
That said, I'm often the wide-eyes client after the first massage for I typically hire the same masseurs repeatedly and upon discovery of one that I really like, it's like damn, struck gold, pay the man and make it worth his while so he'll be agreeable to the next session.
I've also read commits on threads regarding tipping masseurs in that they're comparable to other well-paid professionals as in doctors, lawyers and CPAs where tipping is not the norm. I would dispute in that every lawyer and CPA I've worked with has always padded their billable hours and my last two primary care physicians recently began charge concierge fees between $3-5k a year which isn't cover by insurance nor accessed to my annual out of pocket. Point being, gratuity has established itself in every service profession in this country but simply referred to in sectors by another name.