But at Netflix' scale? I mean Netflix has a relatively fixed offering, something that will fit in a unit in a datacenter with content updates at most once a week, whereas Youtube gets 500 hours of video uploaded every minute.
Netflix small fixed library is significantly better for cache hits.
Google and Netflix peering boxes mean that ISPs with peering boxes at the same peering point can download as much as they want, within reason, for free from that peering box.
You might be confusing CDNs with peering boxes. As might I.