The main objective of this study is to investigate the perceptions of academic librarians towards the marketing of library services through social networking sites (SNSs) and their understanding of using electronic word-of-mouth (eWOM) as a marketing tool in academic libraries. This study follows a qualitative data-gathering approach of structured interviews with ten academic librarians in Malaysia. The qualitative data was analyzed thematically. The academic librarians showed very positive perceptions for the implications of eWOM. Librarians expressed the view that academic libraries could use eWOM as a marketing and promotional tool for creating awareness of library services, promoting library services and building relationships with user communities through SNSs. Academic librarians indicated that eWOM could be used as a very fast medium of communication and for instant responses; it could also be worked as a virus. This study is limited to the perceptions of only ten academic librarians, thus it cannot be generalized to all academic librarians in Malaysia. This paper will be helpful to academic libraries in the marketing of libraries through SNSs. This study also contributes to the growing body of knowledge on the marketing of library services in academic libraries.