I tried doing this to my book collection a few years ago. Things that I found: * Scanning ISBNs had a failure rate of at least fifteen percent, including findi

I tried doing this to my book collection a few years ago. Things that I found: * Scanning ISBNs had a failure rate of at least fifteen percent, including finding the wrong title, or no match at all. * Many of my books did not have ISBNs. For these, using the Library of Congress number often worked, but you have to open the book, find the number, and keyboard it. * About one in twenty of the books had to be completely entered by hand. * Using multiple lookup services helped, but only to a degree. I got sick of it after a couple thousand books, and never even got to the paperbacks. I should add: Thirty clams a month is insane (I just saw the pricing). I'd never, ever pay that in rental -- I might pay up to twice that /once/ for a well-written app which stored its index in a place that I controlled. A good FAQ to add: What's your security story? I'm putting an inventory of potentially valuable stuff into your site, how do you ensure it's not going to leak?