About the Authors: John Hagel III is a principal in McKinsey & Company, Inc.'s Silicon Valley office and a leader of the firm's Interactive Multimedia Practice. He is the coauthor of the bestselling book Net Gain: Expanding Markets through Virtual Communities. Marc Singer is a principal in McKinsey's San Francisco office, where he coleads the firm's Continuous Relationship Marketing Practice.

Some reviews from Amazon.com:

Amazon.com: No one ever said consumerism was easy. At one end, the poor consumer faces a bewildering array of goods and services. On the other, vendors contend with a diverse and fragmented marketplace that makes finding the right set of customers akin to finding the proverbial needle in the haystack. And in between are the billions misspent on muffed purchases and broken marketing campaigns that serve only to stuff mailboxes and alienate the very customers that vendors are trying to attract. The rise of e-commerce has only intensified the problem by offering consumers even greater choice and vendors more competition. John Hagel and Marc Singer think they've got a better idea, and in Net Worth, they present an online scenario that would end this chaos and give both customers and vendors what they really want. At the heart of Hagel and Singer's solution is the "infomediary" that sits between the customer and vendor. For the consumer, the infomediary acts as a trustworthy agent who knows the needs and habits of the client. For the vendor, the infomediary is the holy grail of consumer behavior, a marketer's dream. The infomediary brokers client information to vendors in exchange for goods and services for the consumer.

The result? Happy consumers, satisfied marketers, and a very lucrative business model that awaits those entrepreneurs and companies that are bold enough to embrace the idea. The authors painstakingly outline the challenges and opportunities of developing an infomediary business and go as far as to peg the potential market cap of a dominant player at $20 billion by its fifth year of operation. While the idea of software agents is nothing new, Hagel and Singer may be breathing new life into the idea at just the right time. And even if infomediaries never arise, following the thinking of Hagel and Singer is well worth the price of admission. For marketers, managers, entrepreneurs, and just about anyone who thinks about e-commerce. Highly recommended. --Harry C. Edwards

Wall Street Journal, December 7, 1998 "Anybody running a traditional business who feels threatened by the onset of electronic commerce should feel more threatened after reading John Hagel III's new book. Unless they feel inspired to make its message work for themselves."

Publishers Weekly, February 8, 1999 "Looking at the future of e-commerce, Hagel and Singer... add a provocative twist to the conventional view that those companies with the best information about their customers will be the most successful.... Well-written and full of scenarios of how these infomediaries will develop, this book will interest marketers who are eager to explore the electronic frontiers of the economy."

Business 2.0, March 1999 "To get a handle on the next potential revolution--starring an empowered consumer and diminished brand importance--executives at companies big and small will be speed-reading this one."