When displaying single products, you can use article numbers (ASIN, or ISBN for books).
However, lists (e.g. Bestseller, New Releases) be an exception due to the fact that we need to use the id of the specific product group. Only when submitting the so called “Browse Nodes”, the Amazon Product Advertising API will return exact results.
Note: When using a browse node, Amazon's API returns a maximum amount of 10 products.
How to get the Browse Nodes
Here you can find an overview of the most important main groups (for Amazon.com):