The biggest reason I am against requiring publishers, bands or artists paying to have their music streamed though? One word: Payola. If the owners of music have to pay to have their stuff heard, then only the stuff owned by the deepest pockets will get heard. We already complain quite loudly about manufactured bands and artists who have no real talent, are airbrushed, auto-tuned and managed to a fare-thee-well by the big labels. The labels spend a lot of money finding good looking people who are suitable for such exploitation, massaging the image etc etc. They want and need to get that investment back. Pouring money into radio and internet stations would just become part of that investment. If you think that having to pay for play would convince the labels to only focus on bands/artists with *talent* that the consumers want to hear, in sufficient variety, you are clearly not living in the same universe I do.
Any broadcaster or streaming site pretty much has to choose a playlist based on highest bidder, they are in it to make a profit after all. The only question is; who do you want to be the highest bidder? The music owners=Payola, The advertisers who want music we like to be played so we'll listen (traditional radio and paid access only streaming download sites) Or the actual listeners? (Satellite and some cable-only "radio stations") Everyone involved between the original creative spark and your ears needs to make a living. As I said, I'm spoiled by free radio, streaming and downloads, so I favour the ad supported model rather than the payola or subscriber models. That lets me get my music for free and still have more sense of influence over what is being played.
I deeply miss Yahoo Launch, free music I could rate, build custom playlists with and so on. There were unskippable ads, a programmed halt in playing every once in awhile to make sure I was at the keyboard and an annoying tendency to play artist interviews/behind the scenes and the odd "top 40" track no matter how vigorously and thoroughly I downvoted that stuff. But even with those annoyances, it was my favourite source of music when at the computer for a long time. Nothing I have found since has quite satisfied me. Currently I am alternating between using the Songza website, the Firetube plugin and Minitube for Linux. I've thought about adding a shoutcast server to my home server machine and building my own playlists, but that wouldn't satisify my desire to get *good* recommendations based on my admittedly eclectic tastes. (early delta blues, the latest death, thrash, symphonic and nu metal, dubstep, electroswing, taiko drums, even the occasional bit of crunk)