Purchase Circles provide a unique look at sales patterns. You can access them programmatically only with screen scraping.
Amazon’s purchase circles are specialized bestseller lists broken down by geography or organization. If you visit the Friends & Favorites page, choose “Purchase Circles” from the drop-down list, and type the name of your city, chances are you’ll find what’s uniquely popular among your fellow residents. Amazon also lists what’s popular at universities and large corporations. If everyone at Microsoft is reading about a certain technology, you may find it in the next version of Windows!
In fact, you can link directly to the Microsoft Corporation purchase circle:
The six-digit code at the end of the URL is the Purchase Circle ID for Microsoft. Every purchase circle has a unique ID. You can find IDs by noting them from URLs as you browse circles. The purchase circles home page (http://www.amazon.com/exec/obidos/subst/community/community.html) is a good place to start.
Once you know an ID, you can link to it directly using the URL format. You can also write scripts to access the page and retrieve a list of items.
This script takes a Purchase Circle ID and returns the books listed. Create a file called get_circle.pl and add the following code:
#!/usr/bin/perl # get_circle.pl # A script to scrape Amazon to retrieve purchase ...