Retail Strategies on the Web: Price and Non–price Competition in the Online Book Industry
研究了1999年4月107本书在13家在线和2家实体书店的价格，发现网上和实体店平均价格相近但网上价格差异大，亚马逊的高溢价间接表明产品差异化。
Two conflicting predictions have emerged regarding the effect of low–cost information on price. The first states that all Internet retailers will charge the same low price for mass produced goods. The second states that Internet retailers will differentiate to avoid intense price competition. Using data collected in April 1999 on the prices of 107 books in thirteen online and two physical bookstores, we find similar average prices online and in physical stores and substantial price dispersion online. Analysis of product differentiation yields no clear results. The substantial premium charged by Amazon provides indirect evidence of product differentiation.