Share of wallet (chapter 2)

• Timothy L. Keiningham, Lerzan Aksoy, Alexander Buoye and Bruce Cooil. “Customer Loyalty Isn’t Enough. Grow Your Share of Wallet.” Harvard Business Review, October 2011.
• Timothy L. Keiningham, Lerzan Aksoy, Luke Williams and Alexander J. Buoye. The Wallet Allocation Rule: Winning the Battle for Share. Wiley, 2015. Study description from the authors’ excerpt in Forbes, September 26, 2011.
• Rex Yuxing Du, Wagner A. Kamakura and Carl F. Mela. “Size and Share of Customer Wallet.” Journal of Marketing 71(2), 2007, 94–113.

The adjacency record (chapter 3)

• Chris Zook with James Allen. Profit from the Core. Harvard Business School Press, 2001. Bain & Company, book page.
• Chris Zook. Beyond the Core. Harvard Business School Press, 2004. Bain & Company, book page.
• Chris Zook and James Allen. “Growth Outside the Core.” Harvard Business Review, December 2003.
• Alistair Corbett and Chris Zook. “Hard-core growth.” Bain & Company, April 26, 2004.
• “Chris Zook: Breaking the growth barrier.” Management (New Zealand), February 24, 2004.
• Chris Zook. “The New Rules for Growing Outside Your Core.” Harvard Business Review, via Bain, May 4, 2015.
• Preston G. Smith. Review of Beyond the Core. Product Development and Management Association.
• Chris Lauer. Review of Profit from the Core. Businessweek, June 10, 2008.
• Phil Rosenzweig. The Halo Effect. Free Press, 2007.

Distance and fit (chapters 4, 5)

• David A. Aaker and Kevin Lane Keller. “Consumer Evaluations of Brand Extensions.” Journal of Marketing 54(1), 1990, 27–41. Summary of findings and replications in Echambadi, Arroniz, Reinartz and Lee, INSEAD working paper 2006/08.
• Lorraine Sunde and Roderick J. Brodie. “Consumer evaluations of brand extensions: Further empirical results.” International Journal of Research in Marketing 10(1), 1993.
• Paul A. Bottomley and Stephen J. S. Holden. “Do We Really Know How Consumers Evaluate Brand Extensions?” Journal of Marketing Research 38(4), 2001, 494–500.
• Raj Echambadi, Inigo Arroniz, Werner Reinartz and Junsoo Lee. “Empirical generalizations from brand extension research: How sure are we?” International Journal of Research in Marketing 23(3), 2006, 253–261.
• Franziska Völckner and Henrik Sattler. “Drivers of Brand Extension Success.” Journal of Marketing 70(2), 2006, 18–34.
• Chenming Peng, Tammo H. A. Bijmolt, Franziska Völckner and Hong Zhao. “A Meta-Analysis of Brand Extension Success.” Journal of Marketing 87(6), 2023, 906–927.
• Barbara Loken and Deborah Roedder John. “Diluting Brand Beliefs: When Do Brand Extensions Have a Negative Impact?” Journal of Marketing 57(3), 1993, 71–84.

Cases (chapters 6, 9, 11)

• YETI Holdings. Form S-1, July 1, 2016; Form 10-K for 2019, February 2020; Form 10-K for 2024, February 24, 2025.
• Allbirds. Form 10-K for 2023, March 2024; fourth-quarter 2023 results, Form 8-K, March 12, 2024; Form 10-K for 2024, March 2025.
• Warby Parker. Form 10-K for 2024, February 27, 2025.
• Citigroup. Form 8-K, exhibit 99.1, January 31, 2005. Amey Stone and Mike Brewster, King of Capital: Sandy Weill and the Making of Citigroup, Wiley, 2002.
• Consumer Financial Protection Bureau. “Consumer Financial Protection Bureau Fines Wells Fargo $100 Million for Widespread Illegal Practice of Secretly Opening Unauthorized Accounts.” September 8, 2016.
• U.S. Securities and Exchange Commission. Press release 2020-38 and order, Release No. 34-88257, February 21, 2020.

Cross-buying and nudges (chapters 7, 8, 10)

• V. Kumar, Morris George and Joseph Pancras. “Cross-buying in retailing: Drivers and consequences.” Journal of Retailing 84(1), 2008, 15–27.
• Werner Reinartz, Jacquelyn S. Thomas and Ganaël Bascoul. “Investigating cross-buying and customer loyalty.” Journal of Interactive Marketing 22(1), 2008, 5–20.
• Denish Shah, V. Kumar, Yingge Qu and Sylia Chen. “Unprofitable Cross-Buying: Evidence from Consumer and Business Markets.” Journal of Marketing 76(3), 2012, 78–95. Denish Shah and V. Kumar, “The Dark Side of Cross-Selling,” Harvard Business Review, December 2012.
• Amit Sharma, Jake M. Hofman and Duncan J. Watts. “Estimating the Causal Impact of Recommendation Systems from Observational Data.” ACM Conference on Economics and Computation, 2015.
• V. Kumar, Rajkumar Venkatesan and Werner Reinartz. “Performance Implications of Adopting a Customer-Focused Sales Campaign.” Journal of Marketing 72(5), 2008, 50–68.

Launching and partners (chapters 11, 12)

• Vanitha Swaminathan, Richard J. Fox and Srinivas K. Reddy. “The Impact of Brand Extension Introduction on Choice.” Journal of Marketing 65(4), 2001, 1–15. doi:10.1509/jmkg.65.4.1.18388.
• Adam M. Brandenburger and Barry J. Nalebuff. Co-opetition. Currency Doubleday, 1996. And “The Rules of Co-opetition,” Harvard Business Review, January–February 2021.
• Federal Trade Commission. Updated Guides Concerning the Use of Endorsements and Testimonials in Advertising, June 29, 2023.
• California Consumer Privacy Act, Cal. Civ. Code § 1798.140 (definitions of sale and sharing) and § 1798.120 (right to opt out). California Attorney General, CCPA overview.