There's a big difference in usage patterns: Netflix has a small number of videos, each with huge viewer count. That's eminently cachable. Youtube otoh is the lo

There's a big difference in usage patterns: Netflix has a small number of videos, each with huge viewer count. That's eminently cachable. Youtube otoh is the long tail, orders of magnitude more videos with small view counts. Some of it may be cachable, but that's going to shave off on the order of 20% of the traffic cost, whereas in Netflix's case the gain could easily be 99%.