Recently, mobile content sharing applications incorporating gaming features have attracted much interest. This paper investigates motivations for using these games. We used the TAG framework to analyze motivations based on the recipients of the content, the type of content created, and the goals behind content creation. Participants maintained a one week long diary, and selected participants were called for an in-depth interview. Results suggest that motivations for creating content include knowledge creation, self-expression, creation/maintenance of social relationships, self-presentation, competition and achievement. Additionally, we found that games and mobile content sharing are mutually reinforcing. Implications of our work are also discussed.