I think we all know that QR codes have other applications too, other than being a rather elaborate way of typing URLs. Here we were discussing the use of QR codes on business card. If I receive a business card I don’t want to be entertained or have to use my phone to be able to read it, I want contact information. If there’s room for the code in an unobtrusive way it probably wont hurt, but don’t rely on it to communicate anything important by itself.
I’m sure QR codes can have a role, but for now it is still mainly “all show and no go” and it might continue to be so. My impression is that it is still the kind of technology people like the first time they see it because of the novelty factor, which then quickly wears off and it becomes an annoyance or pointless. I admit I liked it the first time I saw it too.