Nat Gertler, quite the enterprising fellow, has cracked the Amazon.com image code. In his article, he breaks down the makeup of the image source path from adding discount tags to rotating the image to placing text on top of the image.
Abusing Amazon Images
Wow thats really neat. I just went on the site and started messing with a product image. Added a little circle saying 99% off. :D
This is cool, you have to try it. I guessed 60170, and this game guessed it! See it here – http://www.funbrain.com/guess/