Emily Davis presents information on QR codes in September 2011. QR codes are 2D barcodes that can be scanned by smartphones to access various online functions, such as websites, contact info, videos, or initiate actions like placing calls or texts. Davis explains how QR codes are being used by large companies and smaller businesses, the necessary hardware and software to use them, best practices for implementation, and statistics on who scans QR codes and where they are found. She encourages using QR codes as a low-cost marketing tool to drive customers online and stay ahead of competitors.