Is it a problem to change the meta keywords dynamically depending on the content of the page / website?
for example if it is a news website and this weeks top articles are about elephants in japan I would change the keywords accordingly, and when that article is less popular I would replace them with other key words
Technically I know it is not a problem.
How do search engines treat this kind of behvaior? I know that if the keyword list is too long they can ban websites.. What about the rate of change for the keywords?
<meta name="keywords">
tag at all, since it's been abused for so long. So as far as they're concerned, you can put anything in there that you want.