Heather knows the real reason for savings cards (re: the entry entitled "the world today"). Safeway is essentially paying you for your information. Assuming you go in knowing what you are buying before knowing there's savings on the items in question, of course. (Otherwise, you're a schmuck, and they're paying you to get in the store and buy crap you don't need.) Lucky me has a card that's still registered to "New Customer" at an address and phone number both unknown to me and Safeway. Granted, it's slightly less convenient, since not knowing what it is, I can't give them a phone number if I forget to bring the card, but it's a burden I'm willing to shoulder. Safeway has yet to revoke this card (or call me Mr. Customer), so I get the savings but without giving away my information.
Essentially it's a trade. Your information for a few cents off food. Or your social insurance number to...actually, I hate having to give that out. But you get the idea. If you want something, expect to pay for it, somehow. Nothing is free.
(Except if you cheat, like my above example. Then you get stuff for free.)