I've monetized my own YouTube channel by offering online courses.

With a very small channel I've seen some quick revenues.

My stats:
- 12 videos
- 150,000 views approx.
- 2100 subscribers

Revenue:
- on YouTube = $0
- from online courses sold through YouTube - $10k+ per month

If you're interested I put together a series of blog posts about how to do this here:
http://blog.thinkific.com/?s=youtube