Brings up an interesting possibility. Could one set-up their own little business selling, oh I don't know, widgets and then use the debit card to purchase their own product (for the miles of course)? I could sell a widget to myself and use the debit card to pay for it. The money comes out of the debit account, I get the miles, and the proceeds are funneled back into the business (i.e. my bank account). Not sure if this is legal, although I can't see why not.