This paper investigates how academic librarians perceive the role of social networks in enhancing the professional skills of library staff, and how they can be used to promote library services. It is based on case study design in real organizational settings, which are two academic libraries in Jordan, namely the University of Jordan library and Al-Balqaa’ Applied University library. The authors used questionnaires to collect the required data in order to investigate the perceptions of library staff in relation to social networks and how they used social networks to promote library services. The results indicate high awareness and extensive use of social networks for professional development. However, it appears that social networks were not fully exploited to promote library services. It was noted that "job title" (staff position) was the only factor that affected the results, while other factors such as gender, experience, frequency of use and age had no effect on the results. It is concluded that academic libraries in Jordan should make better use of social networks to promote library services.