Many hacks and features depend on knowing a product's Amazon ASIN; here are a few ways to track it down.
ASIN stands for Amazon Standard Item Number, and every product Amazon sells has one. It's a number that's unique to Amazon, and it is at the center of the Amazon universe. Many pages and features rely on the ASIN, so the first skill needed in tweaking Amazon is the ability to hunt down and gather ASINs.
Finding the ASIN for a book is easy because it's the same as the ISBN. ISBN stands for International Standard Book Number, and is a unique numerical ID given to every book published since 1972. The key word is standard, because the ISBN allows the book to be identified across varied systems. Libraries, publishers, bookstores, and anyone who handles books use ISBNs to identify them. Not only does each book have a unique ISBN, but each edition of the book has its own ISBN. That way there's never confusion between the hardback and paperback versions of a book.
So where is this magical ISBN number? Turn this book around, look at the back cover, and find the UPC barcode on the back. Usually printed just above the UPC is "ISBN" followed by 10 digits, as in Figure 1-2.
You can also usually find the ISBN printed somewhere on the copyright page at the front of the book. Sometimes the digits are separated by dashes, but only the numbers are important. This book's ISBN is 0-596-00542-3.
Finding ASINs for other products, such as DVDs, CDs, or even toys, isn't quite as straightforward. Amazon doesn't use any standard method of identification for other products, so each ASIN is unique to Amazon. A quick way to find the ASIN is to search for the item on Amazon and go to its product detail page. The ASIN will be printed on the page, as shown in Figure 1-3.
If the ASIN can't be found anywhere on the page, you can always find it in the URL. Examine the address of any product detail page, and you'll likely find a series of 10 letters and numbers separated from other sections of the URL by slashes. They're often preceded by ASIN, as in Figure 1-4.