eMarketer recently published an informative study for anyone involved with marketing. “Mobile Barcodes: Trends and Best Practices for Marketers” is packed with statistics and commentary on the growth of QR Codes and other 2d barcode formats.
Even if you do not purchase the report, eMarketer has made a couple of the charts available. The information in them is absolutely valuable for people that are looking to either get started with QR Codes or who want to improve the success of their previous efforts.