It's the friction that makes it useless. I saw a QR code on the window of a Chevy Volt that said scan for Volt info. It would have taken a lot longer to find and use a QR scanner than to just enter Chevy Volt into search on a mobile browser.

If QR scanning was a first class citizen and I could just look at it and instantly get the information, I can see QR being used by real people.