This paper aims to investigate the association between variables of intrinsic and extrinsic motivations, cyber-market mavenism, and information sharing behavior, particularly among social network sites (SNS) users in Iraq.This study depends on a quantitative method to test the variables. The sample contains 388 Iraqi customers or users using social network sites to share information about different products and services. The study conducts a purposive sample to determine the characteristics of users who have much information about different products and services. A questionnaire was prepared based on previous research and distributed to participants. The statistical analysis program (SPSS) for descriptive statistics and PLS-SEM were used to analyze the measurement and structural models to test the hypotheses. The study results showed that altruism, moral obligation, and self-efficacy as intrinsic motivations influence cyber-market mavenism. However, self-enjoyment appears to have no impact on cyber-market mavenism. Moreover, reputation and social interaction also influence cyber-market mavenism. In addition, reciprocity and belongingness have no effect among Iraqi users. Thus, cyber-market mavenism plays a significant role in information-sharing behavior. The reason for such an outcome may develop a competitive advantage for marketers through understanding the market maven behavior on social network sites.