Exactly how the marketing channel works The earliest variation of a sales funnel that I'm able to find is this from 1904 by Frank Hutchinson Dukesmith, editor of the Salesmanship magazine Here, Dukesmith introduced the idea of 4 phases that result in a sale: Interest, Passion, Wish and Sentence. Almost half a century later, an advertising as well as sales exec in the pharmaceutical market, Arthur F Peterson, published the following picture in his book, Pharmaceutical Marketing, Outlining, as well as Sales Educating: