Seems a bit pointless, if you're literally having to live hand to mouth, then I can't see why having the only money you've got tied into a card that you can only use in certain places, and certainly won't help you pay back the money that your mate's lent you, or pay your taxi fare. I know Mastercard is accepted worldwide, but a lot of small shops won't accept card transactions for less than a tenner, and there are still places that don't accept cards whatsoever. And as someone quite rightly pointed out, why would anyone who's short of money and not credit worthy for whatever reason want to spend an extra £20 on what effectively is nothing!
I haven't read the blurb properly as the site kept crashing, but this is one product that just might really be handy to give that son or daughter who's off to university! Presuming once the money's on the card, you can't get it back off, the same as mobile phone credit it could mean that you know your son or daughter will have money to buy food, books etc etc...also if the parent needs to send money abroad to their offspring, perhaps this isn't a bad way of doing it, but to tie up what little money you have onto a piece of plastic seems beyond daft to me...and if you've got loads of money, you'd more than likely have a perfectly good bank account complete with debit card (which is given to you free), or a well know charge card such as American Express!