This is pretty bizarre, but when you consider the support they give writers on their Kindle program, it makes more sense. Would-be screenwriters can submit scripts to Amazon, which will buy the rights for $200,000 if they like it.
They get the exclusive rights for 18 months, and if they don't do anything with the script in that time, then writers can go elsewhere. If, however, they decide to develop and distribute the movie, then they'll cough up a further $100,000 to the budding writer, and give them a chance to win a further $1 million for their annual "best movie" award.
All their prize-winners will also get the opportunity to show their work to Warner Bros., who will take it from there and turn it into a massive blockbuster of a movie, most likely starring Leonardo DiCaprio and Julia Roberts (presumably she plays his Mom), where they all live happily ever after. Even if that's not exactly what you wrote in your script... [Amazon Studios via SlashFilm via TechRadar]