This project would not have been possible without the help of an unnamed e-commerce platform that provided access to the data. The author also thanks Matt Backus, Tom Blake, Jim Dana, Gaston Illanes, Sanjog Misra, Amy Schwartz, Bradley Shapiro, Steve Tadelis, Hal Varian, and Caio Waisman as well as participants at the National Bureau of Economic Research Digitization workshop, Columbia IO Seminar, Winter Business Economics Conference, UC Berkeley, and University of California, Los Angeles Anderson Marketing Seminars for their help and feedback.