Torrent Freak had this article today that discusses how the amount of piracy in Sweeden. In fact, it discusses how it has dropped with the introduction of Spotify. This isn't the only case where access to material impacts piracy. Hulu (US only) has introduced an 8 day waiting period for new Fox episodes, this has lead to an increase in the amount of pirating of Hell's Kitchen. If people are going to pirate Hell's Kitchen, HELL'S KITCHEN!, then why wouldn't they pirate just about all Fox episodes? Limiting access drives people to pirate.
Why are people willing to use Spotify over other streaming services? For one, it's free with ads, but people are also able to share. They are able to share legally too. I am able to access music, which my friends on facebook have shared, from friends back in the US. From people that I only talk to on an irregular basis. My friends are able to share with me, where before I would have had to ask them for music and either bought it or download it. Since, I've decided to forgo using Apple products I'm limited by what is on Amazon or other music sites. Not all of the songs that my friends listen to are on those services. They like a lot of indie music.
I think that it's time for copyright holders to wake up to the fact that people don't really want to illegally acquire music. Sure they'd like to pay as little as possible, but they are willing to have ads, visual or audio, to listen to the music they like. The other good thing about a service like spotify is the fact that on your phone, if you pay, you can access your music there. Access is the important thing. If I've bought something once I should be able to access that product on any device in any manner that I want.
The differences in ability to view copyrighted material drives piracy. If copyright holders want to reduce piracy they need to increase accessibility for users. Users are willing to put up with a great deal of things if they are able to easily access content they want. Copyright holders, like Fox, should figure out a way to include online viewership into their rating system. People don't want to be forced to watch shows when they are on TV. They want to watch shows when they are able to.