Research Summary
Why do some young firms change their business models while others do not? Why do some firms make small changes, while others make more substantial changes? And does industry context matter? Drawing on organizational learning theory and utilizing a unique database tracking 187 young firms through the first decade of the mobile health industry, we examine the role of customers in young firms' business model adaptation. We find a positive impact of customer portfolio breadth (capturing the number and diversity of customers) on both the likelihood and degree of business model change. Importantly, industry segment maturity moderates this relation: customer effects are strongest in the earliest, most uncertain stages. Our study provides a rare view into how a new industry and its young ventures co-evolve.

Managerial Summary
Customers have been viewed as critical in a start-up venture's search for an initial business model, but their role in young firms' business model adaptation has not been examined. In this study, we show that a young firm's customer portfolio breadth is an important driver of business model change, especially at the earliest, most uncertain stages of an industry. Our results highlight the value of customers as sources of knowledge in emerging industries, and suggest that when making decisions about establishing and fostering customer ties, entrepreneurs should consider the number and diversity of those ties in the context of the maturity of the young firm's industry segment.