I have just finished reading “2003 Called; They’d like their URL structure back” and must say that I fully agree with Rae’s advice. Whilst it was nice to reminisce back to SEO in 2003 (I was just-a-learning back then), this is something that I think should be cleared up.
The issue of URL structure is still a question that is frequently asked, mainly from developers who have the freedom to create new site URLs that either 1) run directly from the root domain or 2) are subfolder based. The above article provides good examples of each method along with the history and reasoning why developers, and some misguided search engine optimisers, started to (unnecessarily) favour all pages running off the route domain.
My recommendation would be to structure your URLs according to the page’s location within the site architecture. Having logical site architecture is not only important for users but this hierarchy will also help the search engines determine the importance of the page via its location within the site. For example, if your home page links to a top level services page, which then links to each of your primary services and from there to each individual service page, the architecture would look rather like this:
Using the above architecture as an example, it would be best case for your URLs to reflect the structure of the site using relevant subfolders as follows:
Not only does this indicate the location of each page to the search engines, but users will be able to determine where they are in the site (which is particularly important when entering the site through an internal page as opposed to the homepage). Having a sense of place on the site is one of the most important elements for a usable website as this helps users feel at ease and in control (albeit implicitly).
Two of the most effective ways to communicate sense of place on a site is by a breadcrumb trail and by the structure of your URLs. I would therefore always advise structuring your URLs according to the page’s location within the site architecture.
As a side note, it is also good advice to include relevant terms into your URL as this will help inform visitors (and search engines) as to the content present on that page. There are also other points to consider if you are rewriting URLs, most notably to correctly implement permanent 301 redirects on a page by page basis in order to pass weighting from old pages to new, as well as link ‘juice’. (However we would advise that you should rewrite URLs only if absolutely necessary).