The literature recognizes the potential of social media as an alternative channel for promoting the causes of social movements, but little is known about the factors that act on the endeavors by social movement organizations to expand their base of sup-porters in social media environments. Drawing on theories of resource mobilization and social networks, we present a framework for studying how the presence of in-fluential actors or users with a high number of followers in online social networks, can influence the acquisition of new followers by a social movement organization. We collected Twitter data from a major organization in the global justice movement and found evidence that suggests a relationship exists between influential actors and the audience acquired by the social movement organization. However, our model suggests this relationship dwindles as the popularity or number of followers of in-fluential actors reaches extreme large values. Our study sheds light for addressing future questions concerning the factors that drive the propagation of ideologies in social media environments raised by actors of social movements and other social figures in their efforts for bringing about social change.