I'm not talking specifically about YouTube. I was using video in general as an example.
I mean the difference between the US search results and the UK ones. Obviously this varies according to competition but it is far easier to get a video onto the first page of the US results than the UK ones. It's as though Google keeps a "slot" open for video on every results page. They also prefer fresh videos to older ones.
If I am working on a US site (I don't mean the really big stuff like mortgage, forex, health care, viagra etc) I can normally expect to get a video well ranked. If I'm doing a UK site, I cannot. Given the choice, I'd rather work on US sites anyday.