This article presents the results of an inductive, multiple-case study of the transportation brokerage industry. Insights from the organizational behavior and entrepreneurship literature help to sharpen understanding of how organizational structure and entrepreneurial culture relate to firm-level trait preferences in personnel hiring and promotion decisions. Using an inductive, theory-building approach, a typology of four different organizational structures within the transportation brokerage space is proposed. Working propositions are presented that relate organizational structure, entrepreneurial orientation, the differential prioritization of proactive personality and self-management at various stages of career progression, and perceptions of firm performance vis-á-vis competitors. Contributions to theory and practice, and the broader implications for supply chain intermediaries are discussed.