said by someshawguy :
what makes you think ISPs don't have their own CDN? please..i'm trying to state the obvious...
I'm sorry, but I guess I'm missing what you mean. Instead of "trying" to state it, could you just state it?
ISPs might have a CDN for their own content, but it is specifically YouTube that we are talking about here. Perhaps Google might hire CDN services from regional ISPs, but I would still consider that to be part of "the YouTube CDN."