For years, Amazon Studios has held an open call for concept and script submissions. You could send an idea to the company and not only make it publicly available, but (if you were lucky) see it developed as an honest-to-goodness Prime Video production. However, you'll now have to scramble for an alternative. Amazon is closing the open call on June 30th, 2018. You'll still have access to the companion Storybuilder and Storywriter tools, but you won't be showing Amazon the fruits of that labor.