Another tricky issue with live streaming is that often people don't listen all the way through, especially the first time. I might give a song 15 to 30 seconds before I realize "oops - this wasn't what I was looking for". I know this from looking at the web server reports from my own web site - the streamed byte counts are sometimes less than the file size. (You can derive neat statistics from that, like where in the song do you lose people.)

The download and buy model is a lot easier to understand for all parties concerned, and requires less tracking of expiration dates and play counts, but I think in that case the songwriter is due the 8.5 rate. Unless Congress invents some new lower "digital duplication" rate to help out the music delivery industry at the expense of the songwriter. Sounds like something this Congress would do, but I would support anyone lobbying against it.