Amazon Web Services delivers almost all filmed media in the United States to your screen of choice. How are they leveraging that power? When Amazon announced that it would buy mini-major movie studio MGM in an $8.45 billion deal, I surmised that the real goal here was to raise the cost of acquiring filmed entertainment for its competitors, making Amazon’s bundled Prime Video option look more attractive. I also nodded to the fact that Amazon is a competitor in streaming video and theatrical movie production, while also being a distribution network for streamers. Amazon also sells other streaming services through...