I just got a shopping card a few days ago from Bank of Nintendo in the mail.I tried to use the card at select retailers because that what the card says to use it for. Which retailers.
Heheh. He's talking IN GAME in Animal Crossing City Folk. After you save your first 100K? bells, you get a Shopping Card sent in the mail to your character. It is a debit card for use in town at Gracie Grace so you don't have to carry around bags of money. At 1 Million bells you get a Gold Shopping Card that does the same thing. It's kind of pointless, but cute.