When I do a search, a store that I know has my book doesn't show up in your comparisons.

When you perform a price comparison on AllBookstores.com, our robot goes out to each of our many stores, and checks their prices in real time. There are many factors that can cause a store to be excluded from a comparison, and they are:

• The stores web site is down.

• The stores web site is under a heavy load, and not responding to our robot in the time allowed.

• Network congestion on the Internet.

Most of these issues are only temporary, and are resolved automatically when the above problems are resolved.

One of your merchant coupons is not valid.

Our merchant coupon offers are provided to us not only by the merchants themselves, but also by you, our users. Sometimes these coupons do not have expiration dates, and the only way we know that they've expired is if you tell us. Please contact us if you've found an offer that has expired or just doesn't work.