YouTube partners are independent video creators and media companies who are looking for online distribution and who meet our qualifications. Becoming a partner gives you the ability to share in ad revenue from your YouTube videos.
Which percentage will you get? We don't know yet, we know who can partecipate:
1) You create original videos
2) You own the copyrights and distribution rights for the content you upload
3) You regularly upload videos that are viewed by thousands of people
4) You live in USA or Canada
How many people create content?
According to a study (8 months old) only "0.16 percent of visits to Google's top video-sharing site, YouTube, are by users seeking to upload video for others to watch".
Beside the hype of Web 2.0 (or even 3.0) that's the reality now: every user can create content (such as video, article, photo) but only a tiny minority is doing that. Few prosumers (producer and consumer at the same time) and a lot of consumers.