In this paper we explored why people want to share knowledge in the virtual community setting. Taiwan provides an important model for the study of knowledge sharing in online social networks because of the large number of users of these in this country. Using a model modified from the theory of reasoned action and data collected in Taiwan, we found that self-esteem, absorptive ability, and trust are the driving forces of sharing. We did not find that the expected return had an impact on knowledge sharing. Although these results may be counterintuitive, they confirm today's open business environment, where unexpected returns usually go to those who have deep involvement.
