diberry - 3:52 pm on Jun 30, 2012 (gmt 0)
+1 Jinxed. Backlinks may be the main thing with Penguin, but there are sites with very spammy backlinks still ranking, and sites with clean link profiles that got hit.
Penguin and Panda are both more complex than just one factor, and they are both measuring many of the same sites/queries. There's going to be some overlap and conflict.
But how that conflict is getting resolved, I'm not sure. There was a Panda update right before Penguin, as if Google thought Panda would wipe out the weak sites and make it easier for Penguin to catch the spammy sites. But then a Penguin refresh came before the next Panda, which would give Panda a chance to "rescue" some borderline sites from Penguin. At least, that's my understanding of how the computations are happening - if I'm oversimplifying, I'll yield to correction.
I also think it could work the other way - if Panda pegs a site as weak, that might influence Penguin to assume spam when it's unsure. That could explain the false positives with Penguin (I know, not everyone believes there are any). I have a site that I was expecting to get Panda slapped any day. Around April 19 (the Panda update right before Penguin), my traffic slipped a little, but not anything out of the ordinary peaks and valleys. Then to my surprise, I got the Penguin hammer - clean backlinks, no spam tactics. I had SEOs look to see what I had done that got mistaken for spammy, and they couldn't tell me. Google says there's no penalty. Was I really Penguined, or did I get a Panda slap, and then Penguin looked at something like my high number of editorial outbounds and concluded spam based on the Panda slap?
Whatever the case, I'm confident we need to THINK of Panda, Penguin and the regular algo as one big whole, or we'll miss something critical.