I vaguely remember this question being answered somewhere here, but my search didn’t turn up anything.
What is the deal with Duty Free shops?
Is it duty free because the space in the airport just beyond the international exit gate (or whatever you call it) is somehow not officially in any country? How did such an idea ever arise, it seems strange that you would designate some space that is internationally neutral and use it to sell cosmetics, tobacco, alcohol, and chocolates. It seems like a private company that runs the duty free shop, so it’s a wierd mixture of a commercial venture and, what, some sort of tax haven? There is something about those shops – to me – that is somehow unsavory, like kitschy Las Vegas unsavory.