Yea I agree with the registering, but even for those who are unfamiliar with the copyright laws. if I am not mistaken, new changes in laws were made within the last 5 years which allows any artists (producer or rapper) to claim original ownership as long as they can prove they created the work before someone else. the "poor man's copyright" involves sending yourself certified mail of your lyrics or beats, you're not suppose to ever open it unless required (such as a court case to prove who originally created the music).
The ad money that Youtube makes is cool, but until you begin to get big views on your uploads, you're not going to truly eat off of it. for the most part (and this is just me) I view Youtube as nothing more than a place to learn, connect and share.