Good Question! I personally believe in experimenting to see what works and what does not however you must also take into consideration what your content is like site-wide. On one site i have i have all <meta> keywords and description the same as the content is the same through out the website evolving around that one topic, this site is now PR4. On another website content changes and is not so specific on this website i have a unique <meta> tagging on all pages to reflect that of the content on the pages.

So depending on your website content if it is a lot of different material it would be better to have a unique <meta> data for each page.

Hope this is of some use.

Technically you should have unique meta tags for each page as each page is judged on its own merit. Especially the meta description tag which may be shown in the SERPs.

But it really a big deal since since meta tags don't affect search engine rankings anyway. Having the same ones on every page won't affect your rankings or hurt your site in any way except for what I mentioned above.

From other discussion I have gathered that

1. Meta keywords are almost obsolete ...

2. meta description is used as a the text in search results some times (or most of the times) but does not really count in your ranking but people will read it before they click your link ...

So with that said I would not bother with meta keywords at all, and maybe focus on having a unique description for each of your pages (something similar to your title for each one)

As for myself I have a site with more than 40 pages and all of them have the same exact meta keywords and description with no penalties (at least apparent ones)

I believe every page should have unique keywords and description meta tags. For me, it's a usability issue.

I was kind of surprised that no one has mentioned the fact that if you have the same meta keywords and descriptions for each page, there is a MUCH higher chance that google will throw that page into the suplemental index, essentially making sure no one ever sees that page in a result page. Whenever you have pages on your site that are very similar, google is forced to pick an "authority page" this page is then used in the regular results, and the pages not deemed as authorities are dumped into the supplemental index.

^^^^^ I have a site of more than 40 pages and all of them have the same exact keywords and description meta tags for almost a year and a half now, i have been enjoying some nice traffic from all the search engines (no supplemental results whatsoever)

That's a myth.

If it were true, I suspect it was from years ago when meta tags played a more important role.

It dont think this is a myth, do a google search for:

site:www.completecounselingsolutions.com

I'm sure that much of it has to do with the sites having the same title tags, but meta descriptions probably play a role with sites that have little else in the way of on page content such as these.