Forum Moderators: coopster
From [google.com ]
It's also possible that we're not able to crawl your site due to technical reasons. A few of the most common ones are listed below:Your pages are dynamically generated. We're able to index dynamically generated pages. However, because our web crawler could overwhelm and crash sites that serve dynamic content, we limit the number of dynamic pages we index. In addition, our crawlers may suspect that a URL with many dynamic parameters might be the same page as another URL with different parameters. For that reason, we recommend using fewer parameters if possible. Typically, URLs with 1-2 parameters are more easily crawlable than those with many parameters. Also, you can help us find your dynamic URLs by submitting them to Google Sitemaps.
However they don't seem to rank very well compared to other websites using mod_rewrite or similar to emulate a static page. It could be that their content is better or they have more backlinks but this doesn't appear to be the case.
I am in the process of getting rid of pages with querystrings in the URL and using mod_rewrite. I suggest that you do this from the start just in case Google et al do rank dynamic pages using querystrings less well than seemingly static pages.