Recommended URL structure for products and categories in MVC app?

Question

For example, suppose I have a site with products and product categories. I'm trying to come up with a good intuitive url structure. I want to use name slugs throughout rather than database ids. In general I'm not a fan of query string parameters (e.g., www.example.com/products?category=tools) so where possible I'd like to avoid them.

Example URLS:

product list:

www.example.com/products

single product:

www.example.com/products/hammer

this is fine and I have this working. Where it gets more complicated is where I want to add categories.

all products in a category?:

www.example.com/categories/furniture
www.example.com/products/furniture
www.example.com/products/by-category/furniture

What about new products?:

www.example.com/products/new

Or products under $10?:

www.example.com/products/under-10

What makes sense? Is there some kind of convention? Is there an article about this? I would imagine the rails community would have covered this (although not using rails myself) but I can't find a resource. One thing about using products/some-filter is that its competing for the same namespace as individual product listings and there is a potential for a clash.

UPDATE

I should add that there is not a strong hierarchy so it doesn't make sense for a single product to belong to a category as it can belong to many categories. So a url such as www.example.com/tools/hammer (where hammer is a single product) wouldn't work.

When I look at this site (and other stack exchange sites) for tags they use:

http://ux.stackexchange.com/tags

and questions with a given tag:

http://ux.stackexchange.com/questions/tagged/urls

and a single question:

http://ux.stackexchange.com/questions/26340/recommended-url-structure-for-products-and-categories-in-mvc-app

Treating tags as analogous to categories this would give an analogous structure of:

www.example.com/categories
www.example.com/products/by-category/tools
www.example.com/products/hammer

Answer 1

This is how I like to think about it, and it's the way Google suggests it in their "SEO Guide" which gives it credibility with my boss ;). You should be able to remove the end "directory" and get relevant content.

http://clothing.com/mens/shirts/three-wolf-moon
http://clothing.com/mens/shirts
http://clothing.com/mens

If you wanted some kind of filters you can do something along the lines of:

http://clothing.com/mens/price:0-10/color:red

Then, to avoid duplicate content you would just use a canonical URL for products:

 http://clothing.com/three-wolf-moon

I think these urls are the most friendly.

Answer 2

It might help to draw out your hierarchical structure of your data (which I'm guessing might relate strongly with the hierarchy of your navigation); then build up your URL's based on this hierarchy. For instance:

     /-- about us   
home --- contact   
     \-- products --- furniture
                  \-- tools     --- hammer
                                \-- saw

For filters like price range, I would suggest using parameters, because these filters are not strictly hierarchical and (like you said) would compete with a hierarchical filter like "furniture".

So in short: If there is a strong hierarchy use www.site.com/products/tools/hammer; and if there is not a strong hierarchy, use parameters www.site.com/products/tools?pricehigh=100.