Book excerpt: Dot coms will come and dot coms will go, but one thing is for sure: technology and the Internet have forever changed the way we communicate and do business. Two computer scientists from Minnesota are at the vanguard of the revolution. Their creation is collaborative filtering, and it's turning out to be an incredibly subtle and effective tool for every company that uses it. To test CF, John Riedl and Joseph Konstan built two online companies: GroupLens and MovieLens. These Internet sites allowed users to customize their preferences for movies and news. The results were astounding: MovieLens could recommend a movie with 90% accuracy, almost insuring that the recommendation would prove enjoyable. And the potential application for other companies is amazing-anyone from Land's End to Clinique can use CF to build customer profiles and sell products, goods, and services to consumers. The authors analyze dozens of brick and mortar and Internet companies including Kraft, Zagat, Expedia, and Wine.com, examining what these companies are doing right-and what they're doing wrong. They then map out a broad range of strategies that any company can employ to raise revenue and customer loyalty and satisfaction. WORD OF MOUSE will be the first book to bring collaborative filtering to the business community.