It's considered class to tip 20%.
So at BWW when I only get a $2.50 Sprite, and hang around enough to get several free refills, then leave a $2.50 tip, what does that mean?
When I worked as a barista, we took turns using our bras as tip receptacles. We got much more generous tips!
I have to ask ... did you use your own bras, or did you buy special tip receptacle bras in the venti size?
When I was a barista, we took turns using our bras as tip receptacles. It resulted in better tips.
Tits = tips!
tipping is not common here, but one could not argue with the merit of that chart