Modern academic publishing is based to a large extent on the use of the Internet, and many of us consult articles or even books mostly in PDF format rather than hard copy. URL links to both reference material, and data sets or complementary material the author makes available to the reader are becoming commonplace, and are easily accessed from within a document that is consulted in electronic form.
However, in some cases the document can only be accessed in paper, which makes following a URL awkward. Examples of this could be some editions of books available only in paper form, or CVs (as discussed in this question on SE: Is it advisable to have many hyperlinks in an academic CV?).
In similar circumstances, both the manufacturing industries and the marketing sector tend to use QR codes that are easily scannable from a mobile device, such as this one containing the URL of Academia on SE:
To date, I have personally never seen the use of QR codes in academia.
My question is therefore: what major factors make the use of this technology less likely to become commonplace in academic publishing - or more likely, as the case may be?
Edit: thanks to a comment below, my attention has been brought to some scientific books by Elsevier and O'Reilly that do contain QR-codes to enrich content with online material. In both cases, the field were Computer Science and Technology in Medicine.
academia.stackexchange.cominto a browser many times more convenient than using a smartphone with the appropriate app (my smartphone, new about two years ago, has no native QR reader and almost no space for new apps) to scan it. Not to mention I can easily write down the URL, and remember it.