This is either a great idea or a bad idea. It’s hard to say which. That depends on how you feel about being assaulted by these when you open a magazine and find one of these paper-thin USB key ads. Mind you, that’s along with those paper re-subscribe slips and perfume pages.
But it is a neat concept. They can be made to order, are super slim, and can fit in small places. But chances are you won’t be interested enough in any ad content to actually load up what’s on it. At least I wouldn’t be motivated.