Many marketers think of customer intelligence as a key resource in the development of campaigns. However, the future of marketing may not lie in campaigns, but rather, conversations. As the mass advertising of Madison Avenue continues to lose its luster and even targeted, direct mail marketing falls off a slope of diminishing returns, it may be time to take "viral" or "buzz" marketing -- or whatever you want to call it -- much more seriously. Conventional marketing is losing its credibility. So where does one find it?

Word of mouth. That's the answer that the next wave of marketers -- including Tremor, an enterprise backed by Procter and Gamble -- have come up with. According to a recent piece in New York Times Magazine, "The thinking is that in a media universe that keeps fracturing into ever-finer segments, consumers are harder and harder to reach; some can use TiVo to block out ads or the TV's remote control to click away from them, and the rest are simply too saturated with brand messages to absorb another pitch. So corporations frustrated at the apparent limits of 'traditional' marketing are increasingly open to word-of-mouth marketing."

One new agency, BzzAgent, has a network of 60,000 volunteer "agents" who go out and spread the word about products they find compelling. Tremor works on the same model. Turns out, these agents -- who may say a good word on everything from a new book to a great perfume to their friends and acquaintances -- are not primarily motivated by money or other conventional rewards. They seem to enjoy the power, importance and influence they gain by being ahead of the fashion curve.

While researchers have long studied "opinion leaders" and the "diffusion of innovations," the marketing industry may now -- through trial and error -- be generating some important new insights about word-of-mouth persuasion. As Steve Knox, Tremor's CEO, said recently, ''We set out to see if we could do that in some systematic way."

Can they do it? Will marketers successfully build new and valuable networks of influence? Or will consumers "catch on" and start to get skeptical? Will they begin to question the credibility of folks they were once predisposed to trust? Since I haven't made up my mind about the implications of this trend, I'll be listening for the word on the street.