In the following section we present six E-commerce businesses that use one or more variations of recommender system technology in their web sites. For each site, and each variation, we give a brief description of the features of the system. In later sections we refer to these examples as we explain the types of recommendations provided, the type of technology used, and the types of information gathered. For organizational purposes these sites have been alphabetized. The descriptions of these sites are accurate as of this writing, though E-commerce applications of recommender systems are changing rapidly.