The confusing thing was that I was getting good natural listings until I got the ability to put meta keywords on every page, which I duly did. Then, BANG, no listings at all, I am still trying to recover after 2 months! I think it was because I had some irrelevant keywords in this tag (not knowing any better) and am now paying for that mistake. If others do the same i.e. use the tag but not correctly, it will be far more damaging than not using the tag at all. Logically, unless you are confident in what you are doing and understand the rules, its best to leave alone until you do.