A Model of Vertical Differentiation for Online Retailing

The Internet has changed the nature of doing business as well as the nature of competition in many industries. The number of online transactions has seen a steady increase as more consumers turn to online retailing (e-tailing) for a wide range of product choices and shopping convenience. Yet, despite the availability of online comparison shopping sites and the ease of finding alternative e-tailers for a given product, the persistent and substantial price dispersion has not been fully understood. In this paper, we view the online purchase of a product as a bundle of utilities consisting of the satisfaction with the product itself, the service received from the purchase experience, as well as the assurance and trust associated with the e-tailer's brand recognition. E-tailers, accordingly, can differentiate themselves in the service, brand recognition, and price dimensions. We extend the two dimensional competitive model to three dimensions in which e-tailers sequentially decide on a recognition level, then a service quality, and finally compete on price. We solve the model analytically and obtain closed-form equilibrium solutions. By explicitly incorporating differentiation costs, we show the existence of previously unknown equilibria, among which an asymmetric Max-Max equilibrium that is frequently observed in practice. In addition, the e-tailer's optimal competitive strategy is determined by the structure of the differentiation costs