(3)
Let's say you have a very dynamic web site and you also generate your meta keywords dynamically. Could you be penalized (or receive a warning) if those meta keywords are very similar? In a nutshell, yes, though there's a 'debate' across two forum threads.
You may receive a warning in Google Webmaster Tools, but you will probably not receive a penalty. However, as JohnMu says in a Google Groups thread, those "warnings" are mostly nudges that you should try to diversify the meta data. You should keep in mind that the terminology should "makes sense to your users." If that means you need to work with duplicate meta data, then that's how you should proceed.
Forum discussion continues at WebmasterWorld and Google Groups.
Comments:
Barrie Adams
09/09/2008 08:21 am
Interesting point, one I've pondered for a while now, agree that you don't get penalised but surely it's not good practice and in time can only bring problems, watch out for duplicate content on your site!
Leo
09/09/2008 02:21 pm
I thank duplicate meta tags are harmful to your site, because it's not good for visitor. Otherwise, Google is not necessary to tell you.
Brian
09/10/2008 05:19 pm
I've had one instance where a page other than the homepage was ranking number one for a search of a site's name. When I went to webmaster tools, I found that the only warnings were duplicate meta descriptions with the homepage and subsequent pages (it's a blog). So, the homepage had a different title, but the same meta description as page 2, page 3, etc. I changed this situation and the homepage returned to the number 1 spot for the same search less than 48 hours later. Possibly just a coincidence, but I'm not convinced that there isn't some sort of penalty.