Just heard this co on the BBC. (cv3, irish just opening up here)
Pay 3.50 to deposit money and get what AFAICS is a one-time credit card number ...and then pay 1.75 to get back (your own!) unused money if there is any left over.
If enough people used this, there would be more money lost via it, than credit card fraud....and the people subject to "credit card fraud" aren't liable to lose money in any event!
Their USP (on the radio show) was 'dont get defrauded'..IMHO using them IS being defrauded!
I also wonder what would happen should someone get hold of your voucher number and spent it before you used it, I suspect it would be much more difficult to prove it wasnt you that used it, compared to a credit card.