I totally agree with the comment on the OP's blog:
"books have basically been my singular source of investment, more because of the site than in spite of it."
I can't seem to remember how many books I've purchased after downloading them from library.nu. Being in India, library.nu was a gem when a substantial number of books aren't available at Rupee prices.
I also bought the books which I would never had I not had library.nu. Don't tell me about the preview in Amazon, for these particular books I had to see more other pages than "legally" available to make a decision.