Other thoughts:
it is a bit overwhelming with all its options
why is network in cents?
Shouldn't results be ordered by score? Why is something with -20% above something with 20%? but below something with 2%? Confusing.
The navigation links (blog/books/etc) should be available everywhere, as it is the navigation options available once you leave the front page are barren.
Think you should have a bit of an explanation about what the trusting you to impact a user's google results means, rather than just doing it if they happen to click there.
As willarson says, it seems vulnerable to spam (I'm happy to see that 'squeezed books' is what comes up when you put 'business book summaries' in, though:-)
I'm having trouble signing up, it keeps saying this:
"You have specified an incorrect or inactive email, or an invalid password."