A guy tried something similar (called "Can Google Hear Me") a few years ago: http://www.cangooglehearme.com/
It's an interesting concept - Pandora for books. I spent some time looking at it as a potential complementary technology for a reader app I worked on a few years ago.
Fairly rudimentary algorithm at that time, but it's conceptually interesting and worth burning a couple of cycles watching the intro video.