I live in a country where you only tip rarely (if the service is really good) and it isn't by %. When I went to the US I was mind blown that people were leaving 20% of what they paid for as tips.
I'm not roleplaying as the character when i'm playing a game, I don't start acting girly and e-slooting for free **** like some people do "hi i'm a girl, stop hitting on me silly boys...