I would tend to agree with others that it has slowed piracy, but not really improved the problem.
Originally Posted by Onioner
With me, the problem with getting any kind of music for free is that I feel zero obligation to give it attention.
Agreed 100%. I don't and will never illegally download music, but when I get a promo, I listen to it a few times and review it, and then forget about it unless it was absolutely amazing. And if it's really that good, I'll go out and buy it anyways.