Abstract
This paper explores why and how ecommerce firms differentiate their products and services. Consumers who shop online are able to do quick and easy comparison shopping, including shopping in an active market for used goods. Since online product search and price comparisons are faster, easier, and involve fewer shopping costs, firms who sell online must differentiate their products and services to a greater extent than those who do not sell online. These product and service differentiations may be certified and rated by host shopping sites and by outside ratings companies.