Quick facts:

• Dirty URLs aren’t just ugly, but search engines will give slightly less relevance to those pages.
• Clean URLs are attractive, but most importantly – rank higher on search engines!

The following is an example of a clean URL in action:

• Ugly URL:
  www.example.com?servicearea=Northridge&State=CA&ID=3&return=true
• Clean URL:
  www.example.com/Northridge

“B” will rank higher in search engines than “A”, even though the content for both “A” and “B” are exactly the same.