This study examines the individual and social factors influencing the participation intention of viewers andposters in virtual communities. Trust, reward, structural capital, and cognitive capital play significant roles for bothtypes of user. Reputation and reciprocity have a positive impact only on posters' participation intention, whileviewers are also affected by enjoyment. The only social factor having no effect on posters’ participation intention isidentification. Viewing behavior is not correlated with reciprocity and identification. The positive relationshipbetween reward and participation intention is stronger for posters than for viewers. In addition, managerialimplications and suggestions for future research are discussed.