Bear in mind what you are aiming for here. Keywords exist to indicate the subject matter of your website to the spiders that index it for the purpose of determining where to place you. Now, if I am a site that specializes in pet products, and I put the keywords:
dogs, cats, llamas, emus, lemurs, monkeys, horses, pigs, goats,
the spiders will never figure out what I am. They won't understand what I am trying to say is that I have products for any pet you may own. I've tried to cover too much ground and the common thread (pets) got lost. I've diluted my website's theme by spreading out too much.
On the other hand, if you concentrate (focus) on your main strength using the keywords "pet products" and "pet care", which 99% of the people who are looking for you will enter into the search engine anyway, then BAM, you're at the top of the heap. You've correctly and succinclty told the spiders what you are about using the most commonly used search terms to do it.
John Hoarty
jhoarty@quickestore.com