Drawing on empirical cases from Indonesia, this article offers a critical approach to the promise of social media activism by analysing the complexity and dynamics of the relationship between social media and its users. Rather than viewing social media activism as the harbinger of social change or dismissing it as mere “slacktivism,” the article provides a more nuanced argument by identifying the conditions under which participation in social media might lead to successful political activism. In social media, networks are vast, content is overly abundant, attention spans are short, and conversations are parsed into diminutive sentences. For social media activism to be translated into populist political activism, it needs to embrace the principles of the contemporary culture of consumption: light package, headline appetite and trailer vision. Social media activism is more likely to successfully mobilise mass support when its narratives are simple, associated with low risk actions and congruent with dominant meta-narratives, such as nationalism and religiosity. Success is less likely when the narrative is contested by dominant competing narratives generated in mainstream media.