I was just thinking about this the other day: contactless payments is the norm in Australia, having the highest adoption rate in the world[1] I would guess that between 75-90% of retailers accept it? It's always very frustrating when a retailer doesn't accept it.

100,000 contactless terminals across the country[1], the numbers for  Pay usage in Australia would be very impressive.

[1]: http://www.smartcompany.com.au/finance/42250-australia-leads...

[2]: http://www.news.com.au/finance/money/australia-hooked-on-tap...

The security is a little more complicated than that. There are dozens of in-application checks and controls which try to guarantee that you're who you say you are, that you're authorized to make the payment, that you have funds and that the amount to pay is within certain limits. Naturally, a stolen card could be used once or twice. But never for very high amounts and never very many times: the card will request PIN and then the thief is stuffed.

And yeah, like Australia, contactless has been growing in Europe for the last few years. It's just starting in the US and these devices will help to trigger uptake (IMO).

> We've had high penetration of contactless in Australia for a long while now

The problem with credit card payments in Australia is that many merchants charge an additional fee for using it, so I often end up paying cash anyway. This is stupid -- the payment processing fee is a cost of doing business, and should not be passed on to customers (or should be built into the pricing of the products).

The proxy card number doesn't change so why is this considered a feature? It discloses something which is as good as your backing real card number.