I got four of them just with my copy of iLife '06, which suggests that I'll have several opportunities to take advantage of "special offers from Apple" that require these coupons. It hasn't happened yet.
There's more. The card of coupons also warns, "Important: Do not discard these coupons. Only original coupons can be used as proof of purchase. Copies will not be accepted." Wow, "Do not discard" in bold type. Like I said, I've got a stack of these, from various pieces of software. Just waiting for a special offer. Anytime now, Apple. I'm ready. With my coupons.