Sgt_Kickaxe - 4:18 am on May 29, 2012 (gmt 0)
I concur with the effects being at the page level. I've had a handful of pages demoted and a couple promoted to the high filter level meaning most with moderate search safety won't see them. e.g. a group of women won an award in my niche and I wrote about them but the word girls in the title might have hinted at adult content, the page got picked up by adult site linkwheels as an adult link though it's not in any way.
That page wasn't considered adult before Penguin.
Of the pages I have confirmed gone the new top rankings are all product selling sites with massive affiliate programs. My site is informational and there are none of those above Googles own "shopping" links (which seem to demark the end of the big brand shopping portals).
From #1 to #277
From #2 to #589
From #1 to #117
From #3 to #411
There seems to be no set pattern of minus 50 or minus 100 on these pages, the rest hold solid in their ranks for exact match titles and major keywords. These were not major traffic keywords by any means nor did they have a lot of backlinks. I'm going to single out a few and build better backlink profiles to them by mentioning them to a few related webmasters and I will ignore a few as well to see what difference, if any, there is. I bet Google hates when webmasters do that but hopefully not, what else can you do when pages get removed without explanation?