Sales and Rank on Amazon.com

In this note we provide a method for converting sales rank data into sales quantity. We show how sales quantity data can be extracted from product inventories on Amazon for a subset of products. We collect a large dataset using this method and then generalize results from Chevalier & Goolsbee (2003) by estimating the fit of a Pareto distribution model of sales rank for a large number of categories. We provide the outputs necessary to convert rank to quantity for these categories as well as a method for conducting inference on quantities