Mod_rewrite is all the rage in forum search engine optimization these days. For those who don't know what mod_rewrite is, the general idea is to take a dynamic url such as [noparse]http://www.theadminzone.com/forums/showthread.php?t=20341[/noparse] and "rewrite" it using mod_rewrite so it becomes [noparse]http://www.theadminzone.com/forums/does-google-hate-me-20341.html[/noparse]. Some companies are charging well over $100.00 for software that does this, so it MUST be a good thing to do, right? Not necessarily.
Mod_rewrite came about because at one time, search engines were unable to properly follow dynamic urls such as [noparse]http://www.theadminzone.com/forums/showthread.php?t=20341[/noparse]. If you utilized such url formatting, you were destined to be poorly indexed in the search engines. At this point in the internet era, it was a very good idea to utilize mod_rewrite. Your content wasn't being indexed, so why not? Since then, search engine technology has improved a great deal and they now have no problem with the vast majority of dynamic urls. Since search engines can now index the content of your forum even if you have dynamic urls, it is actually a BAD idea to utilize mod_rewrite. But why?
To properly implement mod_rewrite, you utilize a 301 redirect that redirects traffic from the old thread at [noparse]http://www.theadminzone.com/forums/showthread.php?t=20341[/noparse] to the new thread at [noparse]http://www.theadminzone.com/forums/does-google-hate-me-20341.html[/noparse]. It is amazing how many SEO hacks do NOT utilize this 301 redirect which is a VERY bad idea. However, rewriting your urls can hurt you even if your hack DOES utilize proper redirects because, contrary to widespread and popular belief, 301 redirects do NOT transfer inbound link benefits!
Google states in their information for webmasters:
WHY would Google tell you to contact people who link to your site and ask them to change where they link if a 301 redirect transferred it automatically? And then there is the age factor that is incredibly important in the algorithms. When you rewrite your old url, you create a new url that does not have the benefit of time on its side. Therefore, by rewriting your urls, you are losing the benefits of pre-existing inbound links pointing to the OLD url and age.
Many claim, "But having keywords in url is incredibly important for SEO!" I see no proof whatsoever of this. People claim it is important, but when you ask for proof, nobody is ever able to provide any statistical analysis to backup their claim. If you think about it from a Google engineer's standpoint, why would you weight keywords in the url after the initial domain? It is incredibly easy to stuff urls with keywords. If you weighted them in the algorithm, your results would be flawed as it isn't the url that determines quality, it is the content and votes (inbound links).
Run any search engine query and look at the url results you get back. For instance, a query for "css articles" [ame=http://www.google.com/search?num=100&hs=JIS&hl=en&lr=&safe=off&client=opera&rls=en&q=css+articles&btnG=Search](results)[/ame] show the following as 3rd in the SERPs:
Talk about a dirty URL. Yet they are ranked 3rd out of 75 million results. Obviously, you do NOT need keywords in the url to rank high.
And finally, did you know that using mod_rewrite WILL increase server load and page load times?
Let's revisit the facts:
1. Search engines can now handle dynamic urls.
2. Many mod_rewrite hacks do not utilize proper 301 redirects, which is VERY bad.
3. According to Google, 301 redirects do not transfer the benefits of pre-existing inbound links.
4. Rewriting your url destroys any age benefit it once had.
5. Any query you run will return plenty of high ranking pages that do not utilize keywords in the url.
6. Mod_rewrite takes up valuable system resources.
To mod_rewrite or not to mod_rewrite? I hope I have answered your question.