walkman - 1:00 pm on May 23, 2011 (gmt 0)
want the truth? Google sees small web people now as free loaders, they see the clicks as 'theirs' and hate to give them to people making 'easy money.' Their former CEO called it a cesspool when he met with the print media in 2008 and said that brands will clean it up. Meaning, eventually no clicks for you or me, just big brands.
As long as the top sites keep their rankings so Google is not embarrassed they can experiment drastically and take away 70% of the traffic in a heartbeat and even call your site bad.
So, serps now make no normal sense, it's a whole new world and Google is being more honest lately.
But when there's a major update, serps do fluctuate a lot more. And yes Goog can penalize one keyword and not touch the rest, I know it for a fact.