Sorry to be the Maverick in this discussion but the facts on this matter indicate that when it comes to META-keywords you must keep it to three.
Remember, in the process of building your site you are doing one page at a time. Each page should be very specific with regards to its content. The more specific you are the better the results you'll get with your rankings on the search engines.
Think about it this way. How could you possibly write or create a web page that addresses 8-10 or more keywords? You simply can't.
So when someone types in "one" of your keywords, finds your site listed on the first page of the results (hopefully), clicks on your link, they had better find the "exact" results they were looking for. If not, they're gone.
On the other hand, if the keyword they typed into the search field was "oriental rug cleaning" and your page was about "discount oriental rugs" you have failed your visitor and they will never be back.
What's even worse, now that the search engines are monitoring online behaviour of surfers they will penalize your site if your "bounce rate" is above 50%. Also, the search engines will think you're trying to SPAM them when you use too many (8-10).
So, limit your keywords to 2-3 per page. Make it specific and related to the content on that page, and use the "primary" keyword in a text link.
You'll do much better in the long run if you follow this pattern.
To your success