Why is there airport shopping, despite usually being more expensive than anywhere else except for tax-free? Because you have a trapped audience and once you got them wandering their store and find something they like many people will buy it right there. They won't make a note of it that they should check into buying one of those later. The time in the airport and the airplane seat is already a "sunk cost", spending my time shopping when I'm back on the ground is not. It's not cost efficient, but many have more money than time.
I used to travel a bit on an air plane due to work, the in-flight magazine was usually read cover-to-cover because well, there wasn't much else to do after finishing the newspaper. I don't think I'd read a mail order catalog like this seems to be though, but the "infomercial" travel stories, fashion/art items and such I think hit their target pretty well. I mean, it's not every day I read three pages about what's to see in Stockholm/Düsseldorf/Valencia but I know I have done so on the plane. And I'm not the one for buying overpriced crap, but it got me looking and a few times tempted because it was actually stylish.
These days, I'm on the phone. Went flying twice on Friday for a one-day meeting, didn't even consider looking in the seat pocket. Bring your own entertainment and for longer flights the in-flight entertainment system is actually getting pretty good. At least good enough to fill the dead time, which is exactly what companies like Skymall depended on. Which is why I'd love an autonomous car and don't understand the naysayers, spent 2+ hours today watching traffic. I honestly got better things to do, but since I'm driving I don't have a choice.