The dominant online video company said on Tuesday it had 74.8 million subscribers at the end of December and forecast 6.1 million more through March, fueled by its expansion this month into virtually every country except China, where it is exploring ways to launch its service.

The projection is more bullish than the 4.94 million average estimate of analysts surveyed by FactSet StreetAccount.

Shares of Netflix rose 7 percent to $115.42 in after-hours trading.

Netflix, which started sending DVDs to customers by mail two decades ago, now offers its subscribers unlimited online access to TV shows and movies from Hollywood studios plus its own original shows such as "House of Cards" and "Orange is the New Black."

New customers overseas are countering slowing growth for Netflix in the United States, the company's biggest market. It added 1.56 million U.S. subscribers in the fourth quarter, below the 1.65 million it forecast, and less than 1.9 million a year earlier.

"Our high penetration in the U.S. seems to be making net additions harder than in the past," the company said in a quarterly letter to shareholders.

Netflix said it expects U.S. subscribers to jump 1.75 million this quarter. The company will likely benefit from the return of hit show "House of Cards" and a traditional bump in interest at the start of the year from people with new TV sets.

Internationally, Netflix added 4.04 million subscribers, compared with its estimate of 3.50 million. Netflix does not break down where its international subscribers are based.

From January through March, the company expects to add about 4.35 million international subscribers.

"The rollout in 130 countries in early January ensures that they will have no problem hitting their international target," Wedbush Securities analyst Michael Pachter said.

Netflix said it may be able to start a service in China this year, but it may take longer. "We have work and uncertainty ahead," the company said in its investor letter. "Our expectations are modest and long-term."

Netflix said revenue rose 22.8 percent to $1.82 billion in the December quarter. Analysts on average had expected revenue of $1.83 billion, according to Thomson Reuters I/B/E/S.

Excluding items, Netflix earned 7 cents per share, ahead of analysts' average estimate of 2 cents per share.

(Reporting by Anya George Tharakan in Bengaluru; Editing by Sriraj Kalluvila and Bill Rigby)