Meta-organizations (MOs) are organizations whose members are organizations. They are a collective form of organizing and are often coordinated by a secretariat, an entity that is created within the MO. The secretariat is responsible for achieving the purpose of the MO on behalf of the member organizations. We study how the secretariat may contribute to make the MO more effective at achieving its members purpose. We rely on an in-depth case study to show how a business cooperative of organic retailers became what can be labeled as a ‘strong meta-organization’, that is, an organization able to sustain itself and to achieve its purpose while protecting membership by preserving the engagement of its member organizations within the MO. Paradoxically, the member organizations became increasingly dependent on their MO as it became more effective at achieving its purpose. To become more effective, the MO granted its secretariat with three types of control prerogatives: technical, bureaucratic, and political. Therefore, the dependence that members experience when they join an MO may be considered as a necessary evil as it appears as a consequence of its effectiveness, effectiveness being defined as the ability to achieve the common purpose of members. This research contributes to MO theory by highlighting the role played by the secretariat in the effectiveness of an MO. We contend that the MO theory should better integrate the study of the secretariat into this stream of research, making room for more actorhood in characterizing MOs as specific social objects.