Can you reload them with more $$$?
Do they "steal" some of your $$$ as payment?
You can reload them with more money. Typically your parents do that, though. Unless you are employed and want to use that as a credit card-ish thing. And then transfer all that information onto a credit card (not sure if you can do that, but I hear things that some companies allow that). From what my dad told me, since he was thinking of getting me one of these so I don't waste my grandfather's credit account up anymore than I've already done, is that it functions just as L'Viaquez already stated. It's treated like a credit card, but is a debit. You can use it just like you can use any other credit card out there. For example, if you want to by a song on iTunes, you can input that information on your account and it will work (since my friend uses this method of purchasing content from just about anywhere). But as I said, you can continue to refill it so long as you wish.