Imagine you're waiting tables, scurrying around with hot plates, forcing a smile every time someone asks for some extra sauce. ‘Of course’, you say, and run to go get some… for the fifth time that night, for that table. Finally, a glimmer of relief, table 12 wants to pay. They'd been relatively great, smiled politely, said ‘please’, and hadn't bothered you. You'd even had good banter with them, so you expect they'll tip well. No luck, they don't even leave a tip… and their bill is just about $2…