Along with the prevalence of microblogging technology, many companies have been creating microblog accounts to promote their products/brands and communicate with customers. However, it is still unclear regarding what factors are critical and can drive users to follow companies’ microblogs. To fill this gap, the present research develops a research model through the perspective of elaboration likelihood model. According to the elaboration level of information processing, we explicate users’ following behavior through three levels of participation: reading messages, forwarding messages, and commenting on messages of companies’ microblogs. We propose that information quality (the central route variable) and source credibility (the peripheral route variable) are two important antecedents in the research model. In addition, we extend the model by considering the role of similarity and examining its impacts on users’ following behavior. We empirically test our research model by collecting data from an existing microblogging site in China. The results show that most of the proposed hypotheses are supported. We thereafter discuss these findings, point out limitations and opportunities for future research, and summarize this study with implications for both theory and practice.