Brett_Tabke - 12:11 pm on Sep 9, 2011 (gmt 0)

>The question in my mind is the percent of all users/visitors that will actually provide feedback

About quality and not quantity. You've heard of Klout.com right? Google has to have something similar internally. You know the Author thing G released and how they surface reliable content for that? Yep - klout'like internal ratings.