niceThis varies greatly and depends on your videos. You first need to understand the approval process and the different forms of approval. With front page promotion, you can find your videos on many platforms, getting lots of views. This often means $1-3 per thousand views. (But there is no guarantee). With Limited Distribution, you rarely make much. Your goal should be to upload good content frequently and hope the world likes it.
If you're looking for a viral hit with three or four uploads, remember that you're competing with millions of videos per day and viral hits are rare. But strong performers that make you hundreds, or even a few thousand dollars are quite possible.
I try to upload 15-20 videos per month and it has been a steady and respectable income for me since the start, three and a half years ago.
But you'll need to understand what the internet watches and shares to build the best channel possible.
Like any business, it's not effortless, but it can definitely be well worth it!