The Disney Vault has been a marketing and sales strategy for years. After a film's initial release run, Disney would sequester the title in its vault for a long period of time. That meant that customers who didn't buy a physical copy of the movie immediately would be out of luck until Disney brought it out of the vault as a new edition or a special release run.

This strategy allowed Disney to control film sales and drum up anticipation for titles that were coming out of the vault once the company decided the time was right. But it also frustrated customers who ended up paying high prices for copies of movies that were widely unavailable during their vault stints.

Disney has dozens of movies in its vault and in its entire collection—classics like Dumbo, The Little Mermaid, and 101 Dalmatians, and new favorites like Frozen. Locking those movies into the company's own streaming service will make it that much more appealing to diehard Disney fans—and customers who have children.

... exclusivity will be an important factor for Disney as it competes with other streaming giants like Netflix, Hulu, and Amazon Prime Video. In 2017, Disney announced that it would remove its content from Netflix to prepare for the launch of Disney+ in 2019. The picture became clearer as Disney clarified that its movies and properties that it acquired, like Star Wars and Marvel films, would also disappear from Netflix. That content and other licensed properties will likely also stream exclusively on Disney+.