I am surprised that more comments do not share this view. It is a cool technology but i worry that there are too many ulterior motives behind wanting to control your wallet on your phone. I also am not sure if the convenience factor is high enough encourage use. I can already tap my credit card against the gas pump or even at a Starbucks but I think I only done it once. I would not use it to get coupons or targeted ads pushed to my phone. Expense tracking is the only use case that interests me but with so little coverage it would not support that yet. Think what will happen is you will have a Visa app, MC app and an Amex app and then have other apps that will interact with them securely and letting you control your privacy.