[vidarh]

A better analogy would be that a test drive is an advertisement.

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.