One easy way to do that is to find products in a specific Amazon category (i.e., "Countertop Blenders"). To do that, you need to know the "Node ID" of that category.
Problem: Sometimes finding the Node ID is not easy.
Sure, you can use the Browse Nodes response group (people who know the API know what that means), but that's awkward and time consuming.
There are websites out there that supposedly tell you all of the Node IDs for particular categories, but I find them incomplete.
There is an easy way.
Just go over to Amazon and visit the page for a specific category. In this case, we'll look at countertop blenders. Here's the non-affiliate link:
Now, right-click on that page and click "View Source" from the context menu that appears.
You'll see the code for the page. Just search for the word "node". Eventually, you should come across something that looks like this:
Note the highlighted word "node" in the link tag. The number to the right of the equals sign is the Node ID.
HOWEVER, sometimes I have found that the Node ID is not in the link tag. In that case, it's almost always in the link to the category page itself, which exists on that page.
Keep searching for "node" on that page, and eventually you'll see the link:
There it is again. Same Node ID in this case, which is what you would expect because I'm still on the blenders page.
Now, you can use that Node ID to browse for products within the "Countertop Blenders" category.
So if you want to search for blenders, you would use something similar to this (unsigned) request.
Note the "BrowseNode" parameter at the end. That tells Amazon to only search in the blenders category. Yes, I included the keyword "blender" as well because sometimes Amazon miscategorizes products.
I thought I'd share this because it took me a while to figure out how to get the Node ID for various Amazon categories.