Might have to pay a fee to them or something. Just make sure you keep your backup info somewhere safe. Also don't keep a lot on it. I had like $160 worth on mine.

Would be no different than transacting a sale over the net. I buy a lot of stuff from others, that I send payments to that I have to trust they'll send me what I bought. Like with other payment option without recourse, you have to trust the other party.