This may be slightly off topic, but I'm sure other North America users will be in the same boat as me. Why did the Avengers Age of Ultron get released to the world before it was released in the US?
Because they make more money overseas, and helps drive up the interest in the US - resulting in even more money for the studios.
CBS news wrote up a nice article about this a while back.
"We've reached the point now where a blockbuster film can make as much as 80 percent of its overall box office gross outside of the United States," says Dave Karger, chief correspondent for Fandango.com. "So it makes sense that the studios are catering to the overseas markets by releasing many of their biggest tent-pole movies internationally first and even adding special footage in the most important markets."
Paul Dergarbedian, box office analyst for Hollywood.com, says the same thing, releasing movies overseas ahead of the U.S. rakes in more cash worldwide -- and it helps to build hype for the U.S. In other words, don't underestimate the power of cinema jealousy.
"First and most importantly it builds excitement in the countries where the film is not yet playing. In other words, news of blockbuster returns overseas only serve to raise awareness and excitement in North America and as such I believe lead to bigger returns once the film lands stateside," says Dergarbedian. "'The Avengers' last year and 'Iron Man 3' are two great examples of films that opened to bigger-than-expected results in North America due to the fervor and pent up demand for these film by American audiences."
More recently, Kevin Feige addressed this exact question at a special screening of the movie. The answers were reported back to Reddit
Why did it open up overseas early?: [Kevin Feige] says this trend started around Iron Man 2/Thor and they wanted to see how it worked out - he said many countries have holidays [sic] end of April, so it made sense to open it early. They felt no hit in the box office, so it continued. Also allowed distributors to tout foreign numbers going into domestic release
This practice started becoming more common perhaps 15 years ago (coinciding roughly with when large swathes of the world, most notably China, started getting sufficiently affluent to consume Hollywood movies). The main reason given then was piracy concerns.
I don't know if today that is still the main motivation. Perhaps since then they've discovered other advantages associated with an earlier international release.