NEW YORK — Online shoppers subscribing to Amazon.com ’s premium membership are getting a new entertainment feature that will allow them to watch movies over the Internet, just as they can through Netflix’s video subscription service.
Amazon.com Inc.’s Prime membership charges $79 annually for free two-day shipping and low-cost next-day shipping. Beginning yesterday, the millions of people subscribing to the Prime service can also watch roughly 5,700 movies and television shows through Amazon’s on-demand video service, at no additional charge.
The selection will include a mix of movies and TV shows, such as the documentary “March of the Penguins’’ and the 1970s British comedy series “Fawlty Towers.’’ All of those titles are also available through Netflix Inc.’s much larger online video library, which offers more than 20,000 movies and TV shows.
Amazon’s expansion into video streaming still poses a threat to Netflix, which has 20 million subscribers.
The competition from a deep-pocketed rival such as Amazon could make it more difficult for Netflix to attract and retain subscribers looking to save money. Netflix offers a streaming-only service that costs $8 per month, or $96 annually, but most of its subscribers pay more so they can also receive some DVD-by-mail rentals.
With another bidder in the video-streaming market, movie studios may be able to demand more money for the licensing rights. That could raise Netflix’s expenses and lower its profit margins.
“When you have a big and growing market, there will be competition,’’ said Netflix spokesman Steve Swasey.
Amazon’s streaming feature also could hurt cable and satellite TV providers.
The movies and shows can be streamed on computers or through Internet-connected TVs, set-top boxes, and Blu-ray players.