Well, one day you may own an iDevice or a Mac. Or Apple might finally release iBooks for Windows. Or pigs may fly like a Pink Floyd concert balloon*.
Maybe think of the freebies you've already picked up as a future investment? You never know.
* This will probably happen around the time that I personally have success with the iTunes DRM-removal thingy which is floating out there, which I have never been able to get to work.