Box Office Mojo is a website that tracks box office revenue in a systematic, algorithmic way, founded in 1999. In 2008, Box Office Mojo was bought by the Internet Movie Database, owned by Amazon. The website is widely used within the film industry as a source of data. From 2002–11, Box Office Mojo had forums popular with film fans. On October 10, 2014, the website's URL was redirected to Amazon's IMDB.com website for one day, but the website returned the following day without explanation. 

Brandon Gray began the site in 1999. In 2002, Gray partnered with Sean Saulsbury and grew the site to nearly two million readers. In July 2008, the company was purchased by Amazon.com through its subsidiary, the Internet Movie Database. 

From 2002–11, Box Office Mojo had forums, which were a popular place for box office "fanatics", and the site at one time was home to several popular movie games and quizzes, tests (e.g., "Fantasy Box Office" (created in 2006) and "Create a Year of Movies"), until these were summarily canceled for undisclosed reasons. Box Office Mojo had forums with more than 16,500 registered users. On November 2, 2011 the forums were officially closed along with any user accounts, and users were invited to join IMDb's message boards, even though not all the same features were available there. Tracking is still done very closely to the day by day, actual tabulation of distributors, making it possible to see the general trend of a film's "earnings trajectory".
who helped build the site up?
 Gray partnered with Sean Saulsbury and grew the site