Earlier quoted context omitted.
> There is literally a handful of companies who can financially and technically pull it off at youtube-scale. Only a few companies that can do it centrally. Peer to Peer technology was doing it before youtube existed.
Youtube is anything but centralized, they literally pioneered distributed video content with their GGC nodes, with at least 10s of thousands of nodes all over the world. They may not be the first, but almost definitely the largest. I don't understand why you are mentioning peer to peer technology? What does that have to do with anything? Youtube is not a cute side project where your viewing experience depending on ho…
The super-seeding / swarming approach developed for the BitTorrent protocol is quite interesting. One original seeder just needs to upload to a few leechers. Then this leechers become seeders themselfs and start to upload to a next layer of leechers and so on. This approach scales exponentially meaning you can cover the whole internet in just a few steps. Further more you can start uploading yourself even before you have completed receiving the file.
E.g. if every node just has 10 uploading connections then you just need 8 steps to cover 100 million = 10^8 peers. Remember the traffic on the original seeder (and every other node) is just 10 uploading connections.