Even HBO pads out their scheduling with content produced by other companies. I do not see a future where the bulk of Netflix's streamed content is produced by Netflix.
Amazon does a clumsy job at a lot of things. It's incredible. Their shipping and logistics? Top notch. Their server operations, including AWS? Very good. Their website UI? Pants. Utterly pants. Using the Prime Instant website to watch video and using Netflix to watch video is like the difference between night and day. Netflix is well-organized, provides helpful recommendations, and has meaningful categories. Amazon, meanwhile, uses the exact same UI for buying books as it does for browsing streaming movies. And it uses that same UI for office supplies, groceries, clothes and caskets. (Okay, maybe not caskets.) And it's a mediocre UI for all of them.
EDIT: I checked, you can totally buy caskets on Amazon. Wow.