Based on Rogers’s innovation diffusion model, we investigate how electronic word-of-mouth (eWOM) through different types of social media impacts movie sales across the different phases of movie screening. We collected eWOM information on movies from February to October 2012 from Twitter, Yahoo!Movies, YouTube, and blogs on a daily basis. The results indicate that Twitter is relatively influential on movie revenue in the initial stage of opening because of its mass media characteristic. On the other hand, Yahoo!Movies and blogs are relatively influential on movie revenue in the late stages of opening because of their interpersonal communication characteristics. Since YouTube contains both characteristics of mass media and interpersonal communication, we determine that there is no difference in the impact of YouTube on movie revenue between the initial and late stages of opening.