In an effort to increase interaction and brand exposure, marketers have recently begun using flash mobs as a marketing device. This exploratory paper combines a conceptual discussion of flash mobs in a marketing context with a number of studies to understand how marketers are currently using flash mobs and, more importantly, if flash mobs are an effective tool of communication and persuasion? This paper categorizes flash mobs as a subsection of guerilla marketing, and provides a historical and cultural analysis of the phenomenon. The first study, a content analysis of branded flash mobs on YouTube, shows that branded flash mobs are primarily used to promote entertainment, retail and travel organizations, that the majority of branded flash mobs are dance performances, and that they normally take place in a plaza or inside a mall. Through several in-depth interviews (studies 2a, 2b, and 2c), the paper then presents an examination of the intervolved behavior and motivations of branded flash mobs stakeholders: the producers, the audience, and the participants. Implications for the marketing manager are noted and areas of future research are offered.