Corporate Social Responsibility (CSR) in sport is an emerging area of interest among scholars, sport managers, sponsors, fans, and policy-makers (Breitbarth, Walzel, Anagostopoulos, and van Eekeran, 2015). Despite this increased scholarly attention, a gap in literature exists regarding to the effectiveness of the messages disseminated. This study investigated how sports organizations communicate CSR on Twitter by examining the effectiveness of CSR messages disseminated via Twitter by professional baseball teams. Using priming theory and Lang's (2000) Limited Capacity Model for Mediated Message Processing, this study tested the effects of priming and message sequencing on a persons' ability to recognize and recall these CSR messages. While no statistically significant relationships were found, observed results led to strong arguments about the effects of both priming and message sequencing on the effectiveness of CSR messages disseminated by Major League Baseball (MLB) teams in terms of recognition and recall. Additionally, results suggested that traditional media effects paradigms might not be transferable to social media.