ECN Forum Forums Off Topic Discussion Off Topic Discussion From an outsider- How does tipping work?

I don't know how it works in the US but here in Canada if paying by debt or credit cart the payment terminal (or most of them) gives you the option of either allowing you to enter in a dollar amount of your choice or you can hit one of the preset buttons to select a tip %. On Saturday the pizza chain I go to had the presets at 10% 15% 18% and 20%.