The purpose of this research is to investigate factors impact Jordanian customer engagement in electronic word of mouth eWOM on social networking sites SNSs of non-profit organizations NPOs. Through a thorough literature review, the researchers developed a framework to describe the relationships between the research independent, dependent and moderating variables. The research sample consisted of 367 respondents who only have running accounts on at least one of these SNSs (Facebook, Twitter, YouTube and Instagram); and who also have had in seeking or sharing for information about one or more of theseNPOs in Jordan (king Hussein cancer center, tkiyet um ali and injaz corporation). Accordingly, multiple regression analysis has been used; the research findings confirmed that perceived trust in contacts on SNSs, customer involvement in SNSs and perceived usefulness respectively impact customers engagement in eWOM on SNSs of NPOs. Moreover, the moderating role of habit was also supported. Thus, the conclusions of this research, recommendations and directions for other researchers within the same field also have been discussed.