My first year on YouTube (2013) I made roughly $3,000 from YouTube ad revenue.
Last year (2015) I made $14,000.
This year I made $33,000 from ad revenue.
A big jump in revenue has been selling this digital marketing course: http://engineeredtruth.com/digitalmarketing
For the first week I earned $300 in commission, and now I earn about $1,500 a week in commission.
If you already have an online course that you sell then that's great! I'm going to help you create a YouTube channel to help get more organic sales to your course. I recommend using Teachable to create your course, I'm using the paid version, but you can use their free version
I included data of my income in the files, and feel free to ask any additional questions. I'd be happy to answer.