Recently, lot of corporate has spent their budget on WoM(word of mouth) marketing to increase its sales, so many researchers has contributed which variables are effective to persuade their consumers. This study focused on the effect of messengers’ social distance based on increase of using Social Network Service to diffuse contents and message about brand. Although many researches have studied the methodology how well persuade consumers, online environment is changing rapidly. In this circumstance, the role messenger of contents has enormous influence. With this background, our study tested through a 2(Social distance of messenger: close vs. far) X 2(Source credibility: High vs. Low) X 2(Message sidedness: one side vs. two side) between-subject experiment. As a result, we affirmed that we can convince well consumers when the social distance of messenger is close than far. The funny thing is that when the messenger’s social distance is close, source credibility and message sidedness lost their role as variables to effect on persuasion. The other way, source credibility and message sidedness effect on persuasion when the messenger’s social distance is far. We also verified the interaction between these three variables. It makes no difference on the persuasion effect between source credibility and message sidedness when the messenger’s social distance is close. On the contrary, there are statistical differences when social distance is far.