A standard dynamic url will look something like this:
http://www.davidpitlyuk.com/?p=139
There are some major advantages to re-mapping the URL to something more relevant, as well as including select keywords.
Advantages
SEOmoz’s Google Search Engine Factor Rankings sheet lists this as a 2.8/5 in terms of importance. Here’s a bunch of quotes from leaders in the SEO community with their opinions:
Barry Schwartz - Having them bolded in the search results are worth a lot in my opinion.
Aaron Wall - Not weighted anywhere near as much as an exact match domain name, but helps improve CTR (and thus relevancy if CTR factors into relevancy scores) and some people will link to pages using the URL as anchor text.
Ben Pfeiffer - Works very well in Yahoo. Great for user navigation and still worth while to do as a basic SEO methodology. Use hyphens.
Jonah Stein - Information Architecture plays a large role in establishing themes.
Scottie Claiborne - This only influences rankings where you have many sites linking to that page using the URL as the anchor text. This isn’t seen very often as most sites use your site name or a descriptive phrase as anchor text. It doesn’t hurt to do it, but I would never change a page that is already indexed just so that you can add keywords in the URL.
Eric Ward - Again, depends on the content, the source, and the trust earned previously.
Eric Enge - The influence of this one is microscopic. Main value is to help the use understand what your site is about.
Russ Jones - Dependent upon a number of factors including the number of words, dashes and slashes. Also good, though, for CTR (as mentioned above)
Wil Reynolds - Remember this also helps people know what a page in their history is about.
Thomas Bindl - Importance is mainly due to the keyword in links when people use the URL as anchor text.
Mike McDonald - Similar to the domain name, I think it’s always a good thing to have your keywords associated with your address. If someone is going to link to your page, they will by default be linking to your page using one of your keywords.
Guillaume - I’ve seen very little effect on that
Lucas Ng (aka shor) - Not from Google itself, but you will get some pages linking to that page using your URL keywords, so there is that benefit.
Marcus Tandler - Matt himself recently said in a blogpost, that the keyword in a page´s URL might help a little - quote: “Most bloggy sites tend to have words from the title of a post in the url; having keywords from the post title in the url also can help search engines judge the quality of a page.”
Jill Whalen - Same comments as keywords in domains.
Ani Kortikar - dont overdo it.
Chris Boggs - Even Matt Cutts said this helps.
Again though, this is dependent on other factors such as the page content as well as IBL anchor text.
Caveman - Is G helped by seeing that a file has been named “large-long-widgets”? Of course. Even spammers won’t often name files in a way unrelated to page contents. The only reason it’s not more important, is *because* spammers name files according to page contents.
Todd Malicoat - It certainly doesn’t hurt, and provides bolded listings on many search results which assists clickthrough rates. It is good practice, but likely only has marginal value by itself.
Rae Hoffman - Again, depends on the search engine. I think algo wise it carries some importance, but isn’t “needed”. That said, I think having a page named something that clearly says to users “this is about the topic your looking for!” may help increase CTR for the ranks you *do* have.
Roger Montti aka martinibuster - I’m not certain that it helps all that much. Having one keyword in the URL is probably fine. Two keywords, might help the organic CTR (for rankings it’s debatable). Beyond that I think the likelihood of a URL looking spammy goes way up.
SearchEngineWatch did a case study using PlumberSurplus.com and found that the number of pages indexed by Google/MSN/Yahoo as well as the amount of site traffic drastically increased. Check out the results:
Indexed Pages
| Engine |
11/1/2006 |
1/3/2007 |
3/1/2007 |
| Google |
38,400 |
85,600 |
62,200 |
| MSN |
597 |
959 |
2,068 |
| Yahoo |
10,633 |
22,560 |
30,581 |
Site Traffic
| Date |
Visitors Per Day |
| 11/1/2006 |
9,000 |
| 1/3/2007 |
12,000 |
| 3/1/2007 |
13,500 |
There are ways to re-map a URL, whether you are using Apache or IIS as your webserver, but for the majority of us using Wordpress, it’s very easy. By default Wordpress will not remap your URLs, but you can turn it on. Head to your admin, click the options link, and then in the submenu click Permalink:

I use the common date and name based option, but you’ll see many others want a flat structure. In this case they would just specify this in the custom structure and do just /%postname/ and the URL will be domain.com/postname.
Have you switched your blog or site at any time from a dynamic URL and seen some major differences? If so, tell me about it.