According to Van den Bulte, chief marketing officers do not need to be math whizzes to use the model: He and Joshi have developed a handy spreadsheet that incorporates a close approximation of the equations and does the forecasting for executives. Also, the model can easily be estimated employing SAS, a commercial software package popular with market research providers.

Marketers have long tried to deepen their understanding of how new products gain acceptance among customers, a process known as product diffusion. Companies are especially interested in diffusion in markets that consist of two segments: "influentials" (knowledgeable people who keep abreast of product innovations and readily accept them) and "imitators" (people whose purchasing decisions are swayed by their savvier counterparts). Targeting influential prospects who are more in touch with new developments than most people and converting them into customers, the thinking goes, allows companies to benefit from a "social multiplier" or "social contagion" effect in marketing campaigns.

In the 1990s, for example, consultant Geoffrey Moore gained attention with books like Crossing the Chasm and Inside the Tornado, which described how new high-tech products first gain popularity among technology enthusiasts and later among more risk-averse, mainstream customers. Moore's idea of a "chasm" -- that high-tech products often enjoy high sales, then suffer a sales decline, or chasm, before catching fire with customers and rising again -- made him a guru in Silicon Valley.

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