Dynamic content can be a boon to a site. It allows you to address individual user needs, keep your content fresh-looking, and basically do a lot that static content just can’t do. The major problem dynamic content presents for most sites is that the URLs produced for dynamic content are not friendly to the search engines. This can seriously drag your pages back in the results pages.

When do you know when you have a problem with a dynamic URL? Basically, you know because it features on your site. SEO experts habitually change any dynamic or dynamic-looking URL during optimisation so that it at least looks static. Many do their best to discourage clients from using dynamic URLs at all on their site, as this makes SEO much easier. This means that any URL with ‘?’ or ‘&’ featured may need to be changed.

This is a great article on dynamic content and SEO. Dynamic content is really a very pesky issue for on-page optimization. If not handled properly, you might end up with hundreds (if not thousands) of duplicate pages in the search engine index with different dynamic URLs. Any professional SEO definitely needs to know how to handle dynamic URLs well.