Exactly how the advertising channel works The earliest variation of a sales channel that I'm able to locate is this from 1904 by Frank Hutchinson Dukesmith, editor of the Salesmanship publication Below, Dukesmith presented the idea of 4 phases that lead to a sale: Interest, Interest, Wish and Sentence. Nearly 50 years later, a marketing as well as sales executive in the pharmaceutical sector, Arthur F Peterson, released the following image in his book, Drug Marketing, Outlining, and also Sales Educating: