graeme_p - 7:38 am on Oct 11, 2012 (gmt 0)
My site, which was very badly hit on January 19th, also partially recovered starting late on the 9th night UK time.
It looks to me that some part of the page layout algo is being less heavily weighted.
It also tells me that if I do not fully recover the problem is probably the page layout, so how does one optimise page layout? Any guidelines?
My site layout as a logo, one internal link and a search box all across the top. Below that is left nav with a 160x600 "wide skyscraper" ad beneath the (sparse) navigation, a 200x200 square ad on the right within the content, and a large rectangle ad at the bottom. COntent is immediately visible.
I have changed the advertising around over the course of the year, but I have never had more than three ad units (plus Vibrant ad links), one on each side and one at the bottom, and the above the fold ads have been wide skyscraper plus square although I have moved them about quite a bit.