CNET: Cendant sues Amazon over book recommendations

Direct marketing firm Cendant is suing Amazon.com for allegedly violating a patent related to product recommendations generated from past purchase behavior. Amazon has already been sued at least once for alleged patent infringement over the same basic issue. Many patents - seemingly overlapping - were granted in the late 90s and early 00s, most of which have lain dormant. They are somewhat similar to patents granted to various online advertising targeting technologies, which to date have largely remained closeted at various firms that have for one reason or another not yet waged legal battles to attempt to garner licensing fees.