Right. At launch, leveraging ipod marketshare was key. After those same users got locked in to the app-store, the music library lock in became less important.

Right. At launch, leveraging ipod marketshare was key. After those same users got locked in to the app-store, the music library lock in became less important. So they started out by letting you pay extra money to break out of their walled garden. I'm pretty sure purchases made in the ipod era are still drm encumbered today.