Update: Some more concrete details on the deal have been made available now, and it does not bode well for subscribers outside of the United States. According to Variety, the deal between Netflix and Disney is for U.S. distribution rights only.
While the movie distribution models are changing every day, for movies as large as those that Marvel Studios produces there is a standard distribution chain of events. The movies have the theatrical release, a DVD release, then show up on paid television channels. Usually, movies are sold to paid television channels in groups, which is how movies that don’t do so well at the box office end up in the hands of subscription services such as HBO, Starz, Showtime, and Netflix.
With a monumental deal made between Disney and Netflix, as of now, all future Disney properties will be aired exclusively on netflix, when they reach the paid programming stage of distribution. This will not effect previous distribution deals (such as the MCU Movies you can currently watch on Starz), but will mean that Captain America: Civil War will air on Netflix – when the time comes.
The deal not only brings the Marvel properties to Netflix, but also brings Disney’s other powerhouse franchises at Lucasfilm and Pixar along with it. With Disney dominating at the box office, this is surely good news for Netflix, who is already enjoying the popularity of the MCU with the likes of Daredevil and Jessica Jones, and four more MCU series in varying stages of production (Luke Cage, Iron Fist, The Defenders and The Punisher).
As the relationship between Marvel and Disney/Marvel continues to grow, one can only hope it leads to more original content between the two powerhouses.