"If you don't understand that, you shouldn't even participate in the conversation."
This is childish. "If I can't conceive of any other perspective, then you shouldn't open your mouth!!!!"
You can keep asserting what you like, but I don't think what I just said is unreasonable at all.
If I can get a "test drive" of the music whenever I want, all the time, then yes, I'd be less likely to buy it. And so there's likely a crossover point where too "smart" streaming systems will cut into revenue. You see fear of that in e.g. last.fm's restrictions on number of skips per hour for the web player.
But it is pretty clear that a lot of peoples music buying habits involve first getting to know an artist or a specific song via exposure to it. All the music I buy comes as a result of that.
If you stay on a single station very long, you will hear it repeat. Their catalog simply isn't that large. I can name the THREE whole Calvin Harris songs I've heard in ALL of my EDM artist playlists on Pandora.
On the other hand, I've bought a ton of albums from new artists on Amazon that I'd found through those stations.
Of course, now Spotify is just superior in basically every way and I'll happily pay for it (Or Google Music, still debating)