I've always bought products from the Apple Store (occasionally Amazon ;-) but I've never had them do more than a quick glance at the card. I did have one swipe his finger across the picture to see if I pasted another photo on top of a real card.
I suppose their is a way they check it via online.
But they never asked me for anything when I ordered online. At all.
I just put in my college and got the discount. I guess they call and verify? If not they would probably loose thousands. If not more. From people just putting in a school.