http://moz.com/learn/seo/url says:
http://www.example.com/category-keyword/subcategory-keyword/primary-keyword.html
However I am wondering about structuring things this a little backwards from that:
http://www.example.com/primary-keyword/ (this would be an introduction and overview of the topic described by the primary keyword)
http://www.example.com/primary-keyword/secondary/ (this would be a category landing page with snippets from articles within the niche described by the secondary keyword, which is itself a niche of the primary keyword)
http://www.example.com/primary-keyword/secondary/article-title/ (in-depth article on a topic within the scope of the secondary, which is within the scope of the primary)
Where http://www.example.com/primary-keyword/ is the most important page targeting the most important URL.
Thoughts?