Bob Cialdini is a professor emeritus at Arizona State University. He influences almost every marketing, evangelism, and sales decision that Guy Kawasaki makes.

His book, Influence: The Psychology of Persuasion, is the guiding light for how Guy conducts business—and in many ways how Guy lives his life.

In short, Cialdini is the “godfather of influence.” He is to changing people’s minds what Martha Stewart is to changing people's lifestyle.