The RTCRM Interactive Strategy team has long been batting around the use of QR code CTAs in pharmaceutical advertising.
While there have been a few examples, e.g. the accompanying Concerta Ad, that have included QR codes as additional/supplementary CTAs to URLs the use of QR codes is limited.
Should a company be interested in this emerging technology, they should answer the following questions about their target audience: 1) do they understand what QR codes are and how to use them? 2) do they have the technology (smartphones) needed to use them?
If the answer is "yes" to both questions, then I suggest a small test run of print ads with the QR codes. From these tests, brands can begin to understand if this method of response returns better results than 1-800 numbers or URLs.