Facebook's challenge to Netflix, the dominant player in digital film distribution, has been turned up a notch with Warner Bros's announcement that five more films will be added to its stream-for-hire service on the social networking site.

On 7 March, The Dark Knight was made available for a $3 rental to Facebook users in the US; now Christopher Nolan's follow-up, Inception, will go on Facebook, as well as the successful romcom Life as We Know It with Katherine Heigl and the kids' animation Yogi Bear. These "new" titles, each carrying a $4 charge for a 48-hour viewing window, will be accompanied by the first two Harry Potter films, Philosopher's Stone (aka Sorcerer's Stone) and Chamber of Secrets. As "library" items, they will be offered for $3.

No figures have yet been released for The Dark Knight's performance on Facebook, but the number of Facebook "likes" have increased by some 2m since the movie was put online. Inception's "likes" number currently stands at 6.1m, and Facebook's Harry Potter Movie page has some 19m "likes".

Thomas Gewecke, president of Warner Bros digital distribution said: "We're pleased to expand our test with a variety of titles that will appeal to a broad audience," said. "These titles have substantial followings on Facebook."

Facebook's entry into the digital distribution market had an immediate impact on Netflix, the sector's leader; Netflix immediately lost 4% of its share price. Netflix has also had to contend with a challenge from Amazon, who last month offered a movie streaming service to subscribers to Amazon Prime. Meanwhile other media entities, such as the Starz cable TV channel, have imposed a 90-day delay on Netflix streaming its shows. Netflix has responded by moving into exclusive content deals: last week it signed a deal for a 26-episode remake of House of Cards, starring Kevin Spacey.

• This article was amended on 29 March 2011 to avoid any suggestion that Warner's streaming service on Facebook was a joint venture or partnership with Facebook.