Seth Godin used the funnel as a metaphor for the traditional customer journey, described in various terms- as awareness, consideration, trial, purchase, repurchase. His insight was that in the new world of user generated content the funnel could now be flipped and become a megaphone for advocacy.
While Seth tried to breath some life into an insider marketing icon, that linear progression—of broadcasting to a wide audience while hoping that an ever-declining subset of those still standing would end up trying or buying—seemed very familiar. It’s tied to the same, old Madison Avenue intrusion model. You know, the one that says, "A .7% response to a bazillion name list blast should fill the funnel.”