London, October 13 : A low budget horror film has social networking sites such as Facebook and Twitter to thank for its success at the US box office.

‘Paranormal Activity’, shot in documentary style, cost less than 15,000 dollars but went on to become one of the top grossing films in the country, amassing more than 7 million dollars at the box office.

A petition, backed by one million, on the Eventful website for the film to be shown in cinemas nationwide and word of mouth reports on websites like Twitter were credited for the project becoming the fifth most popular film.

"You almost do a double take when you look at that theatre count for a movie in the top five. That''s amazing. That''s unprecedented," The Telegraph quoted Paul Dergarabedian, box-office analyst for Hollywood. com, as saying.

Rob Moore, Paramount vice chairman, added: "We all spend a lot of time talking about Facebook and Twitter and our ability to communicate.

"Here''s a case where it allows people to rally around a movie they care about and for them to have a sense of participation, then tell other people, ''Hey, this is something you should see, too.''" (ANI)