That's a really good example. They talk a lot about AWS, and nearly every service they run is in AWS. If you don't pay close attention, you might think they're all-AWS. I expect that Netflix' AWS pricing reflects that perception.

The exception is serving films. If you watch a film, you receive bytes served by hardware built to Netflix' specification, running in leased space at a mixture of colos and ISPs. That's a really big exception. The third of internet traffic is that exception.