Netflix and Amazon have developed service and delivery models that are personal, easy, fast, and very convenient for users. They've found ways to get low-demand and thus previously hard-to-find products into their customers' hands quickly and conveniently. In the language of economics, they are taking advantage of the "long tail" phenomenon, wherein online purchasing and cheap distribution methods make it profitable for retailers to sell a wide array of items, none of which sells in large quantities. (For more on the concept of the long tail, see Anderson, 2004. For more on the impact of the long tail on libraries, see Dempsey, 2006.) Both companies also recognize how important personalization is to customers. For example, Amazon helps users locate items they are likely to enjoy based on their previous purchases, as well as similar purchases made by other customers: on most product pages Amazon indicates, "Other people who bought this item also bought [a list of other items]." Amazon offers users the option of purchasing new or used items and gives users a range of delivery options. In other words, Amazon makes it very convenient for customers to purchase both popular items and items in the long tail.
