I've been to Copenhagen several times, travelling extensively by public transport. I've never yet seen anyone pay on the bus with cash but you can.
But go to Stockholm and you must use a smartcard (the old prepaid paper strips have been phased out, but might still be accepted if you could still get them?). You won't find any machines at bus stops, so if you don't have a card then tough.
What's more, I don't believe they've yet implemented a proper PAYG system (due to some technical issues) so when travelling by train, you either need to use a machine to pay for the zones you're going to travel in or buy what's effectively a Travelcard.
I think you can arrange this online, as long as you've got money on your account, but it needs planning in advance - not just stepping on a bus and touching in.
People seem to accept it though, and I think our setup will be a lot easier given you can pay as you go, auto top up, and use contactless cards.
Does anyone know if the readers support NFC so that people can use their phones to pay?
I am not sure if it works just now, but some of the mobile wallet systems (e.g. EE's Cash on Tap) make the phone operate just like an ordinary contactless card, although there are a
few subtle differences that I'm not entirely sure about.
I am sure EE has fixed that now, although I have no idea how many people use it - as you need a new SIM card and it's something that requires setting up (and taking money from an existing bank account to top it up). Might as well just use a normal debit card is probably what most people think.
Apple is rumoured to be finally taking wireless payments seriously, so I expect this will be the tipping point. After all, if Apple tells the public about this wonderful ability to tap things to pay - every hipster will want to do it, and every tech blog will be talking about it as if Apple invented NFC!
I know that sounds incredibly cynical, but in my experience there have been a great deal of people playing down the benefits of wireless payments simply because iOS devices don't offer it, and Apple went down the route of barcodes. Now it seems it may adopt NFC and use another technology to allow retailers (and maybe TfL) to communicate with you when your phone enters a wireless payment area - which will be good for Apple (getting a nice kickback of transactions linked to that advertising) but bad for encouraging people to adopt the idea.