I live in the UK, population is 50 million or something like that, and I think I am doing better here than in the US for example - who seem to watch my videos for the least amount of time. I wish I was more appealing to the people from the US, first off the variety of food that you guys cook, omg. Secondly, there are like 350 million of you, so that's a huge pool of people to draw an audience from.
I think population is something to be considered when you work out who likes you and who doesn't. Bigger the better. Maybe the US is just more demanding in terms of quality, maybe its something else. But if I could fix it so that a large country found me appealing that would be great.
If youtube gets Unblocked in China I would even consider learning Chinese! 1.3 billion potential viewers.