Social media demonstrate the massive power of mobilization. However, who are mobilized and how mobilization works are still unknown. This paper proposes the network opportunity model arguing that social media establish virtual proximity, which leads to information dissemination without contact and irrespective of acquaintances or unknowns. Two studies focusing on political consumerism were conducted to examine the model. Study 1 uses 2014 Taiwan Communication Survey and finds that social media diversify the participant of social movement. Study 2 uses Web survey and shows that repeated exposure to similar topic on social media elevates the opportunity of observational learning. Based on social cognitive theory, the increase in observational learning cultivates self-efficacy and promotes social movement participation. It is concluded that social media create “personal mass communication.”
