This research explores how frequent communication and emotional closeness, as fostered by the use of social network sites (SNSs) such as Facebook, influence alumni attitudes and behavior toward volunteering for and making charitable gifts to their alma mater. Research was conducted at a large Northeastern University. First, an exploratory study of interviews and participant observation was conducted in order to better understand how and why alumni currently use Facebook. This was followed by the collection of survey data from 3,085 University alumni. The data were analyzed using hierarchical linear regression, which revealed several significant findings. First, active participation in alumni groups on Facebook positively predicts strong social network ties to other alumni and the University along two dimensions: frequency of communication and emotional closeness. Second, these strong ties have an effect on alumni's attitude and actual behavior toward volunteering for and making charitable donations to the University.