The initiative gives people who buy movies on Wal-Mart Stores Inc.'s online video service Vudu the ability to share dozens of clips or pieces of behind-the-scenes footage on Facebook and Twitter. In each case, a link takes users to a website with the clip embedded.
For its first movie under the system, "District 9," Sony makes available 17 movie clips, five deleted scenes and five snippets of a "filmmaker's log" available for sharing. Some of the shared content is reserved for others who also buy the movie for at least $9.99. A search feature also allows movie buyers to jump to certain scenes after searching keywords in dialogue.
The innovation comes at a time when U.S. home entertainment spending is recovering from falling DVD sales. While standard-definition DVD sales continue to drop, high-definition Blu-ray disc sales are increasingly taking up the slack.
When adding digital forms of revenue, including from streaming services like Netflix, U.S. spending on home movies in the first half of the year rose 2 percent to $8.6 billion, according to The Digital Entertainment Group, a consortium made up of Hollywood studios and consumer electronics manufacturers.
Of that, revenue from the purchase of digital movies was still a relatively small $491 million, although that's up 50 percent from a year ago.
James Underwood, an executive vice president of strategy for Sony Pictures Home Entertainment, said the studio has long seen that making extras available is "one of the motivating factors for purchasing a film."
"We think that will transfer into the digital space as well," he said.
Sony says that 61 percent of active disc buyers are aware of extras before purchasing, and 40 percent of active Blu-ray disc buyers usually watch them.
Sony hopes the extras system can be adopted by other studios and other retailers, like Amazon.com Inc. and Apple Inc. That would mean studios can create extras once and have them available in multiple places. Now, studios tailor different extras in different formats for different retailers.
Amazon, for example, makes trivia and actor bios available using its IMDb movie database subsidiary with no extra input from the studios. Apple includes iTunes Extras for computers, such as the ability to track characters on a digital map of Middle Earth for purchasers of movies from the "The Lord of the Rings" trilogy.
At least one other studio 20th Century Fox says it's interested in participating in the new format for Vudu.
"Setting a standard for it and having more and more service providers take that standard is the way to go," said Mike Dunn, president of 20th Century Fox Home Entertainment Worldwide. "Right now, every service provider is slightly different. You have to build one for this guy and another one for that guy. It's just not cost effective."