Cialdini wrote the 1984 book on persuasion and marketing, Influence: The Psychology of Persuasion. It was based on three "undercover" years applying for and training at used car dealerships, fund-raising organizations, and telemarketing firms to observe real-life situations of persuasion. He found that influence is based on six key principles: reciprocity, commitment and consistency, social proof, authority, liking, scarcity.[5] In 2016 he proposed a seventh principle. He called it the unity principle. The more we identify ourselves with others, the more we are influenced by these others.[6]
The book has sold over five million copies and has been translated into 41 languages.[7] It has been listed on the New York Times Best Seller list and Fortune lists it in their "75 Smartest Business Books".[8] It is mentioned in 50 Psychology Classics.[9][10]
One of Cialdini's other books, Yes! 50 Scientifically Proven Ways to Be Persuasive, was a New York Times Bestseller; and another of his books, The Small BIG: Small changes that spark a big influence, was a Times Book of the year.[11] In 2016, Cialdini published Pre-suasion, which became a New York Times and Wall Street Journal bestseller.[12]
Yes! 50 Scientifically Proven Ways to be Persuasive with Noah J. Goldstein and Steve J. Martin (Simon and Schuster, 2008), ISBN978-1416570967.
The Small BIG: Small changes that spark a big influence with Steve J. Martin and Noah J. Goldstein (Grand Central Publishing, 2014), ISBN978-1455584253
Pre-Suasion: A Revolutionary Way to Influence and Persuade (Simon & Schuster, 2016), ISBN978-1501109799
^Kellaway, Lucy (6 September 2016). "Persuasion tactics fit for a presidential campaign: Psychologist and business book author Robert Cialdini on how to sway people". FT.com. The Financial Times Ltd. Retrieved 15 October 2019. I rang Mr Cialdini to ask if he was helping Mrs Clinton, what he did in the moment before he replied struck me as unusually important. This amounted to a longish pause, and an intake of breath. Very slowly he said: 'It's my policy not to speak about any campaign that's ongoing. The emotions are too deep.'