Good, rational analyis by Gianluca Fiorelli of what could be the key reasons triggering the new EMD (Exact Match Domain) filter on your website (English-speaking websites only) and why most of our emotional negative reactions to it could be seen from a more rational viewpoint.
Extracted from the original article intro: "I don’t deny that Google should have tried to refine better this new algorithmic update, having somehow replicated the same “black or white” mistake done with Penguin, but its purpose is surely laudable and the real complaint should be why the hell Google waited so long before rolling it, if it is true, as Bill Slawski with many reasons suspects, it was something that was patented almost 10 years ago.
It’s this unjustified delay what is causing that also respectable and not spammy EMD sites are now dropping like flies.
Few days ago Dr. Pete wrote an excellent “instant post”, describing and commenting what the Mozcast’s metrics are saying in relation to EMDs and the update. If you have not read it yet, I really suggest you to do it.
And read also the comments, a sort of anthology of everything can be said against Google and Matt Cutts. Somehow it was like reading Webmaster forum into SEOmoz.
The most common reaction was something like this:
"Hey Google, my EMD was totally fine. It had gazillions pages of content with gazillion words. It was all White Hat and legit and useful and You – tricky b*ast*rd – You screw it!"
Surely it is an understandable reaction. I’d react the same way if I were seeing my site falling from the first page into the Index Limbo.
But, let’s try to analyze what that kind of reaction actually tells us."