people used to say "thank you, come again" when you paid your bill at a store or a restaurant, and they actually meant it. that's because it makes sense. "thank you for spending your money here, come back and spend more". now they say "have a nice day" and it doesn't mean a thing. they don't give a shit if you have a nice day so long as they got your money and get more later. they only say it because its expected, kind of like turning on your blinker when you're already half way around the corner.