Transnational advocacy networks (TANs) targeting corporations differ from those targeting states in the strategies they employ, determinants of network effectiveness, and assessments of goal achievement. This article develops a corporate boomerang model to analyze the dynamics of corporate-focused TANs. The model is used to assess two case studies of corporate-focused TANs—targeting the US-based oil corporations Chevron and Burlington Resources—active in Ecuador's Amazon region. In both TANs, corporate shareholder activists played a central role in the networks. The comparison demonstrates that the success of the Burlington TAN relative to the Chevron TAN can be explained by differences in the cohesiveness of the two networks and in the vulnerability of the two targets.