The ideal QR code is the one which represents a meaningful, memorable, familiar, call to action or slogan URLised. Like DriveOneNow.com or dot whatever. Or BigDiscount.com. This URL is printed just below the QR code. So if one cannot scan for some reason one can remember the call to action and check it out later. Real estate agents can QR code a 7675ashton.xxx. (listing address). Problem is finding enough available call to action domains. Some newer TLDs I think come with built in template that are already mobile optimized and these serve as ideal landing pages.