I went to buy a book yesterday, and was surprised to find the e-reader version was $20 but the actual physical paper book was only $10. The e-version doesn't need any human interaction - I pay for it, I have it transferred to my reading device and I start reading. A paper book involved paper, ink, printing, binding, transportation, etc and it's only half the price? You can read more here.
I guess that's how the music industry went - do music stores still exist? Can you still buy CDs?
Interesting lesson in business and economics don't you think?