Notably both Android and iPhone require you to install a third-party app in order to scan QR codes. I think if (when) this changes, QR codes will really become

Notably both Android and iPhone require you to install a third-party app in order to scan QR codes. I think if (when) this changes, QR codes will really become frictionless, since you no longer need to instruct the end-user how to first install a scanner app with a help label next to the QR code. Eventually people will "just know" what to do with QR codes, just like they already know what to do with http:// http:// or www. prefixed strings.