That is something that has always puzzled me - why would anyone buy something at an airport? I can get a shop that sells business clothing, and maybe a gift shop and definitely snack and food shops. But if someone is in the middle of a flight, the last thing they are going to want to do is figure out how to get their purchase home. Not to mention you can find that stuff anywhere else for a lot cheaper. I just don't get how they stay in business.