SNS is in the process of fast evolution as well. This study is about influence of authenticity and interactivity among Facebook Fan Page users. Authenticity is something people form in the process of expressing and sharing information thru SNS Facebook Fan Page. Interactivity is a level of participation of users in the process of expressing and sharing information thru SNS Facebook Fan Page. The focus of this paper is to see the power of authenticity and interactivity of SNS Facebook Fan Page users in a time of crisis. Authenticity is proven as a valuable asset for corporations for it showed a sturdy characteristic even when something terrible happened. When a crisis attacked, high authenticity user group was not willing to change their evaluation on a company reputation and image as much as low authenticity user group. Interestingly enough, the meaning interactivity level was strikingly different from what we expected. The more their level of interactivity, was the more they were likely to change their evaluation on a company in a time of crisis. A serious discussion is necessary for this contraty results.