In the face of stiff resistance to their legislative efforts in national and multilateral arenas, nongovernmental organizations, unions, and others are engaging in marketplace politics to press their social and environmental concerns. While important criticisms of market-based regulation abound, recent research has suggested that this form of politics is not restricted to simple market signals or a singular market logic, so the question of what drives corporate responsiveness remains. Drawing on a statistical analysis of a large data set of marketplace campaigns and in-depth interviews with campaign proponents, consultants, and targeted executives, this article proposes a relational framework for understanding marketplace politics, situating campaign strategies in relation to targeted firms' brand vulnerabilities and corporate social responsibility (CSR) “absorptive capacity,” on the one hand, and parallel actions of key intermediaries—including investment advisory firms and pioneering competitors—on the other hand. I argue that it is influential minorities of consumers, investors, and intermediaries—often in dialogue with targeted executives—who create change, rather than majority, arm's length market movements. Overall, this research enhances the multiplicity of recent case studies by identifying common opportunities and barriers for marketplace politics and contributes to the burgeoning literature within economic geography that is redrawing the boundaries of corporate CSR decision making and capacity building.