Nudge

This study analysed 6,700 websites in an unprecedented A/B test. 

The results proved something that Dr Robert Cialdini had been preaching for years. 

Today, on Nudge, Robert Cialdini joins me again, covering another of his seven principles of persuasion. 

And I share a marketing lesson that (I think) every business needs to know.

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Unlock the Nudge Vaults: https://www.nudgepodcast.com/vaults

See Agent Spark in action at gwi.com/spark

Read Cialdini’s bestseller Influence: https://amzn.to/4prHb7Y

Read the new and expanded Influence: https://amzn.to/43TY0jI

Read Pre-Suasion: https://amzn.to/48hA6Qr 

Read Yes! (Containing 60 Psyc-Marketing Tips): https://amzn.to/48ddNNf 

Join 10,189 readers of my newsletter: https://www.nudgepodcast.com/mailing-list 

Connect on LinkedIn: https://www.linkedin.com/in/phill-agnew/ 

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Today’s sources: 

Bell, T. [Taylor Bell]. (2025, February 13). Inside Trader Joe’s: The genius strategy behind its cult following (and low prices) [Video]. YouTube.

Bornstein, R. F., Leone, D. R., & Galley, D. J. (1987). The generalizability of subliminal mere exposure effects: Influence of stimuli perceived without awareness on social behavior. Journal of Personality and Social Psychology, 53(6), 1070–1079.

Browne, D., & Swarbrick-Jones, A. (2017). The science of persuasion in e-commerce: An analysis of 6,700 online A/B tests. Conversion Rate Experts.

Danziger, S., Levav, J., & Avnaim-Pesso, L. (2011). Extraneous factors in judicial decisions. Proceedings of the National Academy of Sciences of the United States of America, 108(17), 6889–6892.

Drachman, D., deCarufel, A., & Insko, C. A. (1978). The extra credit effect in interpersonal attraction. Journal of Experimental Social Psychology, 14(5), 458–465.

Fang, X., Singh, S. N., & Ahluwalia, R. (2007). An examination of different explanations for the mere exposure effect. Journal of Consumer Research, 34(1), 97–103.

Gladka, A., & Żemła, M. (2016). Effectiveness of reciprocal rule in tourism: Evidence from a city tourist restaurant. European Journal of Service Management, 17(1), 57–63.

Mita, T. H., Dermer, M., & Knight, J. (1977). Reversed facial images and the mere-exposure hypothesis. Journal of Personality and Social Psychology, 35(8), 597–601.

Nicholson, C. Y., Compeau, L. D., & Sethi, R. (2001). The role of interpersonal liking in building trust in long-term channel relationships. Journal of the Academy of Marketing Science, 29(1), 3–15.

Razran, G. (1940). Conditioned response changes in rating and appraisal. Psychological Bulletin, 37(6), 481–493.

Shotton, R. (2023). The illusion of choice: 16½ psychological biases that influence what we buy. Harriman House.

Strohmetz, D. B., Rind, B., Fisher, R., & Lynn, M. (2002). Sweetening the till: The use of candy to increase restaurant tipping. Journal of Applied Social Psychology, 32(2), 300–309.

Zajonc, R. B., & Rajecki, D. W. (1969). Exposure and affect: A field experiment. Psychonomic Science, 17(4), 216–217.

KFC keeps its recipe secret. 

It’s stored in a vault in an unknown location. 

Only two KFC executives know the ingredients. 

Neither are allowed to fly on the same plane. 

But this secrecy is illogical. The recipe isn’t important. 

Today on Nudge, Richard Shotton explains how the secrecy makes customers more loyal. 

He shares his favourite ad of all time, and we run one of his experiments on you. 

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Read Richard’s book: https://a.co/d/fEW7amQ

Sign up for my newsletter: https://www.nudgepodcast.com/mailing-list

Connect on LinkedIn: https://www.linkedin.com/in/phill-agnew-22213187/

Watch Nudge on YouTube: https://www.youtube.com/@nudgepodcast/ 

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Today’s sources: 

Heimbach, J. T., & Jacoby, J. (1972). The Zeigarnik effect in advertising. Advances in Consumer Research: Proceedings of the 3rd Annual Conference of the Association for Consumer Research, 746–757.

Loewenstein, G. (1994). The psychology of curiosity: A review and reinterpretation. Psychological Bulletin, 116(1), 75–98.Zeigarnik, B. (1927). Über das Behalten von erledigten und unerledigten Handlungen. Psychologische Forschung, 9(1), 1–85.

In 1963, the Milgram experiments revealed something unsettling. 

Most people kept administering what they believed were painful electric shocks, not because they wanted to, but because they couldn’t bring themselves to say no. 

In this episode, my guest shares why we agree to extra projects, unpaid favours and unreasonable requests even when we know we shouldn’t. 

I’m joined by behavioural scientist and physician Dr Sunita Sah of Cornell University. She studies how social pressure and conflict-of-interest disclosures can quietly steer us toward yes.

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Read Sunita’s book Defy: https://amzn.to/48LsreG 

Unlock the Nudge Vaults: https://www.nudgepodcast.com/vaults

Join 10,428 readers of my newsletter: https://www.nudgepodcast.com/mailing-list 

Connect on LinkedIn: https://www.linkedin.com/in/phill-agnew/ 

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Today’s sources: 

Milgram, S. (1963). Behavioral study of obedience. Journal of Abnormal and Social Psychology, 67(4), 371–378.

Sah, S. (2025). Defy: The power of no in a world that demands yes. One World.

Sah, S., Loewenstein, G. F., & Cain, D. M. (2013). The burden of disclosure: Increased compliance with distrusted advice. Journal of Personality and Social Psychology, 104(2), 289–304.

Sah, S., Loewenstein, G. F., & Cain, D. M. (2019). Insinuation anxiety: Concern that advice rejection will signal distrust after conflict of interest disclosures. Personality and Social Psychology Bulletin, 45(7), 1099–1112.

Woodzicka, J. A., & LaFrance, M. (2001). Real versus imagined gender harassment. Journal of Social Issues, 57(1), 15–30.

In today’s special end-of-year episode, you’ll hear the best insights from Nudge in 2025.

Hear from Prof. Gerd Gigerenzer, Richard Shotton, Bas Wouters, Philip Graves, Prof. Matt Johnson and a Behavioural Insights Team director. 

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Connect on LinkedIn: https://www.linkedin.com/in/phill-agnew/ 

Watch Nudge on YouTube: https://www.youtube.com/@nudgepodcast/ 

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Today’s Sources: 

Beilock, S. L., Bertenthal, B. I., McCoy, A. M., & Carr, T. H. (2004). Haste does not always make waste: Expertise, direction of attention, and speed versus accuracy in performing sensorimotor skills. Psychonomic Bulletin & Review, 11(2), 373–379.

Bellaiche, L., Shahi, R., Turpin, M. H., Ragnhildstveit, A., Sprockett, S., Barr, N., & Seli, P. (2023). Humans versus AI: Whether and why we prefer human-created compared to AI-created artwork. Cognitive Research: Principles and Implications, 8(1), 42.

Groen, J., & Wouters, B. (2020). Online Influence: Boost your results with proven behavioral science. Amazon Digital Services LLC.

Milkman, K. L., Patel, M. S., Gandhi, L., Graci, H. N., Gromet, D. M., Ho, H., Kay, J. S., Lee, T. W., Akinola, M., Beshears, J., Bogard, J. E., Buttenheim, A. M., Chabris, C. F., Chapman, G. B., Duckworth, A. L., Goldstein, N. J., Goren, A., Halpern, S. D., John, L. K., ... & Van den Bulte, C. (2021). A megastudy of text-based nudges encouraging patients to get vaccinated at an upcoming doctor’s appointment. Proceedings of the National Academy of Sciences, 118(20), e2101165118.

Nisbett, R. E., & Wilson, T. D. (1977). Telling more than we can know: Verbal reports on mental processes. Psychological Review, 84(3), 231–259.

van den Broek, E., & den Heijer, T. (2024). The Housefly Effect. Bedford Square Publishers.

Vennard, D., Park, T., & Attwood, S. (2019). Encouraging Sustainable Food Consumption By Using More-Appetizing Language.

How would you encourage Australians to drive slower?

That’s what today’s guest on Nudge, Adam Ferrier, had to do. 

Being an applied behavioural scientist, he tackled this challenge in a novel way. 

Listen to hear about his interesting campaign, how Jaws killed surfing and the secret behind Derren Brown’s “hypnosis” trick. 

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Watch the bonus episode: https://nudge.kit.com/66dcb18641

Adam’s agency: https://thinkerbell.com/

Adam’s books: https://amzn.to/431eYfD

Sign up for my newsletter: https://www.nudgepodcast.com/mailing-list

Connect on LinkedIn: https://www.linkedin.com/in/phill-agnew-22213187/

Watch Nudge on YouTube: https://www.youtube.com/@nudgepodcast/

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Today’s sources:

Cialdini, R. B. (1984). Influence: The psychology of persuasion. William Morrow.

Shotton, R. (2023). The illusion of choice: 16½ psychological biases that influence what we buy. Harriman House.

Sutherland, S. (1992). Irrationality: The enemy within. Constable.