This study develops a framework for understanding user intentions and behaviors within a virtual world environment. The proposed framework posits that the intention to participate in virtual world is defined by a person’s 1) social identity, 2) attitude toward using the service, 3) subjective norms, 4) attitude toward advertising on the service and 5) enjoyment. The proposed model is tested using data (n=319) from members of the virtual world environment. The results support the multidimensional view of social identity and show a strong positive association between social identity and intention and social identity and behavior, and further, confirm the intention-behavior link. Moreover, the results indicate that social identity outweighs the significance of a person’s attitude and relevant subjective norms in explaining intention and behavior. The results also indicate that enjoyment strongly explains both ease of use and attitude.