bluealtec

most massage places have it  just to ensure boy is properly compensated . It also indicates that more than massage is available.
In some places I noticed boys have their individual minimum tip.
Don't assume that for minimum tip you can do with him whatever you want, some will offer just hand job, some will go all the way but is always will be more than just a massage.
I use my own rate 1000 / hr, 1500/1.5 hr but if minimum tip is higher I pay higher rate.
( I see spoon  answered thread at the same minute so hope I'm not repeating what he says)

It might not be clear to someone new to understand minimum tips in bkk, but indirectly, it refers to what services u can expect masseurs will do. For example,arena has a 700 baht min tip for 1 hour massage, and that includes a hj. Anything more, u will need to add tips. Prime massage on the other hand, has 200 baht min tips, so u cant expect anything extra from masseurs. Doesnt mean it wont happen but unlikely. A min tip of 1.5k above usually means full service. This is usually observe in place like vck. Some massage centers even have diff min tip for diff masseurs, but generally same understanding applies.