Netflix says the number of subscribers to its online television service now tops 50 million in more than 40 countries as the company reported stronger-than-expected earnings.

Netflix shares were up slightly to $US453.40 in after-market trading that followed release of earnings figures that showed profit in the three months ending June 30 more than doubled from the same period a year earlier.

The Los Gatos, California-based online streaming television titan reported that profit in the quarter jumped to $US71 million as compared to $US29.5 million in the same quarter last year on revenue that climbed about 25 per cent to $US1.34 billion.

“Fifteen years after launching our subscription service, we have over fifty million members enjoying Netflix in 40 countries,” Netflix chief Reed Hastings and chief financial officer David Wells said in the letter.

“As we gain new members, we are investing to further improve our content and member experience, and to expand the global availability of our service.”

They credited original programming such as Orange is the New Black with helping drive a rise in subscriptions that it predicted will continue through the current quarter with the addition of 1.3 million more members.

The company reported growth in all of its markets, saying the number of members outside the United States grew to 13.8 million in a 78 per cent increase from the same period a year earlier.

Netflix is set to launch in Germany, France, Austria, Switzerland, Belgium, and Luxembourg in September.

The company said that later this year it will also introduce gift cards to be sold in stores in Canada, Mexico, Germany, and the United States to make it easier to join Netflix.

Since it launched its streaming service in 2007, Netflix has become the world’s leading internet television network. Netflix says it streams more than a billion hours, collectively, of digital films and television shows to online viewers each month.