Given the availability and usage of social network sites (SNS), professional sport teams are drawn to this medium as a way to reach new and foster existing fan relationships. Despite the ubiquity of social media, however, little empirical research is available on how Facebook page attributes, and other SNS strategies, influence user participation. Grounded in the relationship marketing framework, the purpose of this study is to explore the relationship between the page attributes found on team Facebook pages and user (i.e., fan) participation. An econometric model is developed and tested to determine the impact of page attributes on the number of Facebook ‘fans’ from a census sample of 114 professional sport teams. Results indicate that page attributes signaling authenticity and user engagement have the greatest impact on attracting and maintaining a Facebook fan base.