Ask HN: Are QR-Codes used by customers in Europe/America?

I have seen a lot of buz in the last few months around QR-Codes. At the moment I am trying to find out if it's worth to add QR-Codes to advertisments. Advertisment-Space is very expensive. I have to choose what to put on the ad. Something that is not used by customers or confuses them is not what I want to add onto it.

Are there any analysis on the usage of QR-Codes? How many users do actually scan those codes? What target audience fits best?

From my gut I would say: If you have a target audience that is male, 16-26 and is very IT-focused, it would be okay to add those codes. But is this the truth? I have seen QR Codes on Ads for non alcoholic drinks that target women, too. Do they actually use them? Or do they add enough value for my brand to be there even if nobody will scan them?