Hashtags have become a ubiquitous and seminal feature of social media; however, a comprehensive understanding of what motivates and predicts their use is yet to be addressed. To fill this gap, this research investigates motives of hashtag use and their effect on behavioral outcomes based on the Uses and Gratifications (U&G) approach. Through a two-phase mixed method data collection, we distill six motives of hashtag use in the context of Instagram: Self-presentation, Chronicling, Inventiveness, Information Seeking, Venting, and Etiquette. We find drivers for platform use to affect these motives, which, in turn, influence the frequency of clicking and adding hashtags, and the number of hashtags a user may employ in a post. Furthermore, we find potential influencers to be heavy users of hashtags, primarily driven by motives of self-presentation, and to score higher on narcissism, extraversion and self-monitoring than followers. We further assert the need for U&G studies to explicitly acknowledge the nature of social media that allows users to both consume and produce content. The findings hold important implications for social media managers and designers.