This year the movie industry made $30 billion (1/3 in the U.S.) from box-office revenue.
But the total movie industry revenue was $87 billion. Where did the other $57 billion come from?
From sources that the studios at one time claimed would put them out of business:Pay-per view TV, cable and satellite channels, video rentals, DVD sales, online subscriptions and digital downloads.
Read the external link (note: you are leaving Movieguide.org)
http://steveblank.com/2012/01/04/why-the-movie-industry-cant-innovate-and-the-result-is-sopa/