27-year-old Duygu Ical took over the Stadion Kebab & Pizza shop in Vienna's 2nd district two years ago, but told the Heute tabloid that she was shocked by how rude the customers were (the Viennese are pretty notorious for their unfriendliness).
“I wanted to change things so I created a new price list,” she told Heute. Now, a board behind the counter tells customers that if they ask for “a kebab, please” it will cost €3.80. Someone who says “give me a kebab” will have to pay €4 and anyone who barks “kebab!” at Ical will have to pay €4.50 for their meal.
The ploy seems to have worked, and Ical says she hasn't dramatically increased her takings but is happy that the customers “are much nicer now”.
The Local France reported in 2013 that the owners of a café in the south of France also resorted to hitting their rudest clients in their pockets, or at least threatening to do so - with a sign charging extra for customers who forget their manners while ordering coffee.