How the Hell Did This Crap Break a Billion?
I don't understand the appeal.
shareMany have stated it's a kids film. Well, there are lots of kids films that don't do anywhere near what this did.
However...
This is a kids film built around characters kids are very familiar with and seem to love. Even though I don't really personally feel it, I kinda see the appeal of the minions: a lot of it seems to be based on slapstick, they're small like kids, though the search to serve "evil" it's a very tame version of evil, etc.
One thing I think that may have helped the huge global market is that except for a few changes here and there, the minions' language is pretty much the same regardless of the market. When movies were silent, it was easy to sell the (almost) same exact movie to markets outside of the US, just by changing the title cards.
Setting it in the 60s may have helped. It'll never become dated because it's already dated.
As that great philosopher Bugs Bunny said, "Something tells me I shoulda stood in bed."