Start with Why
The book starts with comparing the two main ways to influence human behaviour: manipulation and inspiration. Sinek argues that inspiration is the more powerful and sustainable of the two. The book primarily discusses the significance of leadership and purpose to succeed in life and business. Sinek highlights the importance of taking the risk and going against the status-quo to find solutions to global problems. He believes leadership holds the key to inspiring a nation to come together and advance a common interest to make a nation, or the planet, a more civilised place. He turns to Dr Martin Luther Jr, John F Kennedy, Steve Jobs and the entire Apple culture as examples of how a purpose can be created to inspire a culture together, away from the manipulative society we live in today.
The golden circle
Sinek says people are inspired by a sense of purpose (or "Why"), and that this should come first when communicating, before "How" and "What". Sinek calls this triad the golden circle, a diagram of a bullseye (or concentric circles or onion diagram) with "Why" in the innermost circle (representing people's motives or purposes), surrounded by a ring labelled "How" (representing people's processes or methods), enclosed in a ring labelled "What" (representing results or outcomes). He speculates about the biological factors behind this structure, such as the limbic system.
Lindsay McGregor and Neel Doshi, co-authors of the book Primed to Perform: How to Build the Highest Performing Cultures Through the Science of Total Motivation, came to a similar conclusion: "Why we work determines how well we work."
Great salespeople always start with Who. Then they move to Why, What, and How. And then eventually to When, and How Much. ... Now once you get to the right Who, Simon Sinek is spot-on about beginning the conversation with Why. Why is a game-changer in selling modern technology. 
According to NPD BookScan's mid-June 2016 to mid-June 2017 ranking of printed book sales, Start with Why ranked (without disclosing the geographical region) as the "bestselling leadership book" of that period, selling 171,000 paperback copies.
- Five Ws
- Onion model
- Reflective practice § Borton 1970 – In the 1970s Terry Borton popularized the triad "What?", "So what?", and "Now what?"
- The Infinite Game
- Kerwin, Ryan (February 2013). "Start with Why: How Great Leaders Inspire Everyone to Take Action (book review)" (PDF). Army Lawyer: 28–31.
- Knight-Wallace, Carol (October 2014). "Inspire Teams With Why (book review)". Journal for Quality and Participation. 37 (3): 39–40.
- Kavanagh, Shayne (April 2015). "The Essential Variable in Leadership (book review)" (PDF). Government Finance Review. 31 (2): 56–58.
- Doshi, Neel; McGregor, Lindsay (2015). Primed to Perform: How to Build the Highest Performing Cultures Through the Science of Total Motivation. New York: HarperBusiness. p. 149. ISBN 9780062373984. OCLC 919588003.
Similarly, marketing expert Simon Sinek ... points out that the best brands in the world 'Start with Why.' Understanding why a person or organisation operates—understanding identity—builds the highest levels of brand loyalty.
- McGregor, Lindsay; Doshi, Neel (2015-11-25). "How Company Culture Shapes Employee Motivation". Harvard Business Review. ISSN 0017-8012. Retrieved 2020-01-24.
- Krogue, Ken (6 July 2015). "Simon Sinek Says 'Start With Why,' But Sales Experts Disagree". Forbes. Retrieved 2018-05-01.
- Kauflin, Jeff (June 20, 2017). "The Year's Five Bestselling Leadership Books, And Why They are So Great". forbes.com.