[hugh3]

My problem with all of these systems is the same: I'm disorganized, I forget to charge my phone or bring it along, and so the chances of me having a fully charged, working, switched-on phone with me when I want to buy something are far lower than my chances of having a wallet.

[Lewisham]

This is certainly the case in the US, where you're most likely to have driven somewhere, so you're going to have your wallet/purse as you need your driver's license.

That said, there is still some friction when it comes to using a card... some places want you to sign, some don't, some decide on the day... people offer you a paper receipt for a $2 transaction ("No, I really don't need it.")... it's sometimes finicky trying to deal with a wallet full of cards... It's all not all that much really, but there is still room for improvement.

What I really like about this is the end-run around NFC. NFC really doesn't solve the problem, because is is just as easy to pull out a wallet as it is to pull out a phone. Here you don't need to rummage, you say what you want and go. That's 15-20 seconds of your life back per transaction.