Having had the chance to look at the stats for a medium sized YouTube channel the news is not good if you are thinking about making money from YouTube videos.
The bad news about adsense on Youtube is that 1000 plays brought in only £0.67(GBP). This equates to or £00.00067(GBP) per play or put it another way £670(GBP) per one million views.
The average annual wage in the UK is £25,600 so to earn this amount from YouTube would require 38.2 million views per year. It might be that other people are doing better than this example channel, but it also explains why YouTubers are getting into other commercial tie-ins in order to make money. It also explains why there are so many click-bait type videos on YouTube at the moment.
P.S. "Charlie bit my finger" has had 832M views which would be worth £557,000 in AdSense revenue.