URL Structure - Keywords vs. Information Architecture/Navigation

[rball1]

I'm creating the URL structure for an ecommerce site and was wondering if it's better to structure my URLs according to the most popular way people word their key phrases or by what makes most sense from a navigation perspective.

Let's say I'm selling clothing (I'm not, just an example). I want the site to be open enough so a user can navigate by Person Type (Men's, Women's, Children's), Clothing Type (Shoes, Shirts, Hats), and Brands (Nike, Reebok, adidas).

My gut and past experience say to structure the URLs from the least specific to the most specific:

mysite.com/mens/shoes/nike

But I know "men's Nike shoes" is searched for more than "men's shoes Nike", which would render this URL:

mysite.com/mens/nike/shoes

I know mysite.com/mens-nike-shoes would be best, but the folders setup is what I have to work with.

So which is best for SEO? URLs that play to the structure of the most searched for key phrases? Or URLs that follow the information architecture/navigation of a site?

Nate

[ResslerMotors]

For an overall ranking perspective, exact match is going to be better (all other things being completely equal).  However, websites are never perfect vacuums of comparison.  Regardless of which format you choose, you will still be able to overcome your competition through proper on-page optimization, and great link building.