driller41 - 8:24 pm on Jul 16, 2012 (gmt 0)
What they all have in common: Maybe less than 20% of their entire site content could be considered truly fresh or truly unique. It's mainly a regurgitation of what's already on the web.
I believe this is what Panda would a have been targeted at, remember Panguin is 'spam' penalty. I am wondering what google considers spam these days - onsite duplication is not really spam.