My CMS Ate My Search Engine Rankings
http://www.cmswatch.com/AskTony/Archive/?question_id=33

Byrne, Tony
CMSworks
2004

Abstract:

A dynamically-delivered site in and of itself need not denigrate your search engine rankings. Google and other spiders can follow dynamically-generated pages, up to a point. The key is to have links elsewhere on the site pointing specifically to those pages. If each page results from a purely dynamic query (e.g. using session variables), then you could be in trouble.