Question: I keep hearing that "search-engine-friendly URLs" make a big difference when it comes to getting your site placed higher in nonpaid search results. Is this true? And what exactly is a search-engine-friendly URL?

Answer: A search-engine-friendly URL is a well-formed path that contains a domain, appropriate keywords and a proper directory structure that is free of "dynamic parameters" that pass data.

For example, http://www.lyris.com/marketing-platform/web-cms/ is more relevant for the keywords "marketing platform" and "Web CMS" than a URL based on dynamic parameters like http://www.example.com/33838fjfuowlsjftr/index.cfm?id=1, which displays little information of any real meaning to search-engine spiders.

SEO-friendly URLs contain words and proper filenames only. They do not contain any special characters or spaces (when necessary, use dashes to separate words). Using SEO-friendly URLs can dramatically improve your organic search rankings, simply because they emphasize keywords that actually mean something and are easier to index than numbers and strings.

When a search engine spider comes across a symbol -- such as a question mark (?) after a directory or page name -- the search engine perceives the symbol as a dynamic parameter. Although search engines do follow pages with dynamic URLs, they will generally not read more than two parameters. In addition, they may not be able to assign any relevance to the URL itself, since it may not contain any valuable, indexable information. Despite this, many content management systems automatically generate dynamic URLs with multiple parameters.

Having a properly built URL is a simple task when you are dealing with a static site that does not rely on parameters. As soon as a site relies on dynamic pages, sessions and parameters, it becomes more difficult to stick with search-engine-friendly URLs. The best rule of thumb is to eliminate all use of parameters in the URL and to use masking, aliases and other techniques instead. This ensures that your URLs are constructed properly with keywords, rather than symbols and numbers.