by Nat Gertler Created May 21, 2005. Last updated January 10, 2014. Thanks to Aryeh Leib Taurog for the hover code. Amazon.com feeds out a lot of product images, putting out the same book cover (say) in a variety of sizes and formats. By experimentation, I found that they don't actually have all the sizes and formats stored. Instead, they have a system that generates each requested image. The deta