Word-of-mouth is playing an important role in marketing to the extent that some of marketers believe that this form of advertising is among the most effective and efficient ones. With respect to importance of this issue and significant role of word-of-mouth in today marketing it seems necessary to manage this phenomenon in an effective way and exploit its benefits with taking appropriate actions. In present research it was tried to identify factors influencing spread of online word-of-mouth. To this end, six hypotheses were formulated. After introducing general framework of present descriptive research, data were collected using library and field methods. In order to collect data using field study, a questionnaire with 21 items was developed and distributed to statistical population of the research. The mentioned statistical population comprised of customers with experience of purchasing services from Iran Insurance Company in Khuzestan Province. Then completed questionnaires were analyzed using student’s t-test with software LISREL. Results showed that knowledge self-efficacy, sense of belonging and enjoyment of helping others influenced internet word-of-mouth.