Such mentality would work IF you tipped at the beginning of the visit, not at the end.

Insure is a form of insurance, which tipping is certainly not because it is paid after service is rendered. The word people are thinking of is ensure, but it does not ensure good service, and thats TEP which seems less nifty to folks for some reason...

No touching!

Yeah but if you tell your waitress your going to give her a big tap... she may be less likely to return promptly.

What are you talking about? How much does a yoga class cost these days, anyway? $20+ per class? Try getting a monthly membership there - it's going to be more than $100.