Just to supply evidence to the contrary, I make full use of the five-star scale in iTunes, with each additional star translating to some privilege the song gets as a strict subset of the songs with lesser ratings (e.g. 4+ = always on iPod.) I frequently wish for half-ratings across the board, which would make the full, discrete scale 1-10 :) I imagine I may indeed be in the extreme minority, though.
See, thats key to making the system worthwhile. Your ratings come back to haunt you in a qualitatively different way for each rating. Not that I can see how youtube could do this...
