Msg#: 3678323 posted 8:23 am on Jul 13, 2008 (gmt 0)
If you must add an extension, add one which indicates the content of the file not the technology which generated it. Therefore, an HTML file could usefully end in .html, but gains nothing by ending in .php. Then again - HTML may not be the language of choice for webpages in the future - so play it safe and put nothing there as an extension.
Personally - I like to customise the extension to the site - perhaps a site about Widgets would have pages ending in .widget... probably SEO benefit as well as a chance for added branding.
I believe the general consensus today is to get away from any extensions. And this is what I have seen many websites do.
Personally I think this is very wrong, and my experience is that if your page generates html, give it an .html ending...
I also have non-conclusive evidence that this actually helps your SEO ranking with Google these days. And not just marginally, but by a good percentage.
There is also the benefit of not confusing anyone or anything [spiders,bots,crawlers] of whether URL /cat/sub[/] is a page or a folder. Most of them will try to add an ending '/' to see if they can get into it deeper. And if you do not have the proper mod_rewrite rules set, you are going to have duplicate content. Yes, Google is smart enough to figure it out, but you will still get penalized a bit.