No / Purpose - The aim of this paper is to gain a better understanding of how small technology start-ups learn about a key customer in the context of B2B relationships, and to propose a model of interfirm learning with customers. Design/methodology/approach - Using a qualitative case-based approach, the authors immerse themselves in the development of three learning alliances between technology startups and industry leaders, two successes and one failure, to gain an in-depth understanding of the dynamics involved. Data were collected on both sides of the alliance dyad. Findings - The paper delineates four learning cycles: alliance inception, joint-learning, specialization and discovery. These learning cycles constitute sequences of increasing understanding, cooperation, and higher order learning between the partners; evolving from an exchange of existing knowledge to the joint development of new knowledge. Originality/value - This study contributes to an integration of the alliance and marketing literatures by offering empirical evidence of a different type of alliance, namely the reciprocal learning alliance. It also contributes to broadening our understanding of market orientation in inter-organizational settings. In the context of business-to-business relationships, the study has identified four critical dimensions of learning alliance success, and proposed how they could be measured: Learn about customers; Interact with customers; Customer-specific investments; and Co-develop breakthrough innovations. Finally, the study demonstrates the significant role played by 'committed champions'.