This study examines the impact of online word of mouth (WOM) and expert reviews on movies' box office revenues, both in the U.S. domestic market and in the international markets. Using a sample of 169 movies released in 2008, the study discovered that the frequency of online WOM and the valence rating of expert reviews were significant factors for box office outcomes in the domestic market. The study also found that only the frequency of online WOM was a significant factor in the international markets. The findings suggest that online WOM and expert reviews play a critical role in moviegoers' consumption behavior in the age of the Internet and social media.