I guess that Google has lower indexing priority for pages with query variables, because it thinks they are less likely to contain stuff of long-term value. At least one Russian search engine
says this explicitly in the FAQ, adding it will index more "?"-containing URLs on a site with a higher linking rank. Another search engine says it ignores all dynamically generated pages
*.asp*, *.php*, *.pl*, */cgi-bin/* etc.
Search engines think that "plain HTML" URLs are usually authored by hand and are better literature to search for.
Also, URLs without parameters tend to be shorter are more human-readable. I can understand that
http://dev.openacs.org/forums/forum-view?forum_id=14013
makes sense to those who program, but to the rest of users
http://dev.openacs.org/forums/OpenACS/
or at least
http://dev.openacs.org/forums/1/
would look way more logical.
