Most people don't know what bittorrent is, and even if they know, they wouldn't know how to use it. And even if they knew that, they couldn't tell legit content from viruses.
I buy games on Steam because downloading and installing is a double-click. There are a lot of (admittedly easy) steps when you pirate things, like mounting the ISO and browsing to the crack folder, and re-mounting every time you want to play.
Here's the key: you stop selling content, and you start selling something else.
It sounds very zen, but it's Steve Jobs' opinion:
> "We're going to fight illegal downloading by competing with it," said Jobs. "We're not going to sue it. We're not going to ignore it. We're going to compete with it."
Most people don't know what bittorrent is, and even if they know, they wouldn't know how to use it. And even if they knew that, they couldn't tell legit content from viruses.