It has been a year since the NASDAQ crash. Many of last year’s darlings, such as Kibu.com and Pets.com, have gone out of business; others, such as Priceline and Webvan, may be dead by the time you read this. Even long-standing companies, such as Cisco, that merely increased their profits as a result of the Internet boom have seen their growth horizons pulled back.

The reasons for the crash are multifarious. For the past year, McKinsey has focused on the problem of how businesses can move forward despite the wreckage of killer apps and the submersion of stock options. Capital is still tight, but companies can take steps to create sustainable value on-line. The first is to shift focus from the stock market to the stockroom.

A featured section of this special edition is devoted to business-to-business (B2B) marketplaces. By now, it was thought, they would have proved themselves; instead, many B2Bs that concentrated solely on improving purchasing efficiency are mired in failure. Authors from McKinsey’s Silicon Valley office and from the Firm’s operations and B2B marketing practices share perspectives on where the value really lies for buyers, sellers, and the exchanges themselves. No matter what the size of...