To pay for Google's services? Yes, you would be right.

I meant for contactless payment - I'd be interested to see how an open version of that could ever develop.

Why not just use the contactless card your bank gives you? Or, if you don't want to pay directly out of your checking account, get a credit/pre-paid card? They are all contactless these days, and even the small tea shop that processes card payments through an Android tablet and a small Bluetooth reader is able to accept the contactless cards.

Two reasons:

1. My bank doesn't give me a contactless card

2. It's much more convenient anyway, I don't have to reach into my wallet.