True. But depending on what's you guess on how much it costs for netflix to get a content hour watched by a user(maybe ~$0.1-0.2), streaming costs may become meaningful, and higher streaming costs becomes a strategic disadvantage.

Exactly. Excepting Cloudflare which is free, CDNs are expensive (or at least more expensive than I think people realize).

Netflix says it uses about 3GB of bandwidth per hour for streaming HD-quality video. CloudFront for one will charge you $0.26 for that 3GB-hour. It's pretty easy to see how binge watchers will rack up pretty high CDN/bandwidth bills.