Within three individual essays, this thesis deals with collaborative and confrontational approaches by NPOs towards companies, and the role these play with respect to corporate responsibility. By drawing on social movement theory, nonprofit-business collaboration literature as well as legitimacy theory, it advances our knowledge regarding two topics: First, this thesis provides answers to the question how successful collaborative and confrontational approaches are individually at influencing households' judgements of companies and of NPOs themselves. Second, it extends our knowledge of interactions between these approaches. With respect to individual effects, this thesis demonstrates that both collaborative and confrontational approaches by NPOs exert a significant effect on households' legitimacy evaluations of companies and subsequently their consumption intentions. Legitimacy also appears as important underlying factor influencing households' support for NPOs, with collaborative NPOs enjoying higher legitimacy and thus support from households than confrontational ones. Concerning interactions between these two types of approaches, this thesis finds confirmation for previous suggestions that contrasting NPO approaches interplay - but demonstrates that such interactions clearly present a double-edged sword. By simultaneously focusing their approach on the same company, both types of NPO suffer a loss in their ability to influence households' perceptions of companies in the way they envision as well as their capability of attaining resources. However, if such approaches are applied sequentially, the picture of these interaction-effects become more positive. These results indicate that NPOs with different approaches towards companies are well advised to work together in a strategic manner in order to maximize their success.