I am not saying QR cannot work in large scale. A certain fraction will always be interested. A percent out of million people or more is still a lot of people. 🙂
My analysis is a bit biased geographically. I wouldn’t be surprised if the situation would be a bit different in more developed markets. Here in Finland people tend to be a bit reserved and conservative when it comes to tech (kind of ironic, eh? 🙂 ) except for that hip minority that always has the newest gadget no matter what.