To use any of the Web Services hacks in this book, you'll need a developer's token. The token itself is just a random string of alphanumeric characters that is tied to your Amazon associates account. This token system allows Amazon to track who is using their API and to confirm that anyone using it has agreed to the terms of service. It also enables Amazon to contact developers who are violating the terms of service?whether knowingly or unwittingly. You'll need an existing associates account Section 5.2 to get a token. At the Associates Central web site, you'll find a link to the Web Services Program (http://amazon.com/webservices). From there, click on "Apply for developer's token." You'll need to provide an email and password and agree to the terms of service. It's a good idea to look over the terms carefully before you agree. Here are a few points from the terms to keep in mind while you're developing applications:
Don't query the API more than once per second.
Don't substantially alter the data you receive from Amazon.
Include a link to Amazon somewhere on your site or in your application.
Update any information from Amazon at least once a day (once per hour for prices).
Point to Amazon for any sales.
Once you've agreed, you'll be granted your token. Jot it down and keep it somewhere accessible.
If you're going to customize the hacks or develop your own applications, you'll want to download the Amazon.com Web Services software development kit. It provides sample applications and complete documentation. Here's what you'll find in the kit:
A Web Services user guide as a Word document, PDF, and HTML
Sample applications in Java, Visual Basic, and PHP
SOAP request/response examples
Amazon's Web Services site also has a web forum where you can ask questions of your fellow developers.