Hollywood studio Warner Bros. launched an app on Facebook to allow users to rent & watch full movies straight on world’s most popular social networking site. The landmark deal between the tradition-bound film distribution firm and a social media firm started with release of "The Dark Knight".

Users of the new service will be able to watch the movie for 48 hours from the time of rental. Each movie will cost 30 Facebook credits or US$3.

Speaking on the new service, Thomas Gewecke, Warner Bros. digital distribution president Thomas Gewecke said, "We think this is a new frontier in making our films available. We're going directly to people who are already self-identifying as fans." Facebook CEO Mark Zuckerberg has already declared his goal to make everything social. Some analysts believe that movies on Facebook should not pose a direct threat online movie pioneer Netflix.

Nevertheless, Warner Bros. move worried investors in Netflix. Shares in Netflix dropped 5.8 per cent to close at $194.89 on Tuesday.