driller41 - 8:35 am on May 14, 2012 (gmt 0)
I had around 30 sites hit by Penguin on the 24/4, yesterday the first one resurfaced back to number 2 for it's keywords which is encouraging.
What did I do - the site was just 15 pages, the inner pages were all thin content boiler plate stuff, so I deleted them all to see what would happen and left the home page which is 500 words of original content.
Links - did i touch incoming links, no I am goung to try anchor text dilution on some other sites where I suspect this problem but did not create any more links on the recovered site.
What can I conclude:-
That weak content was the cause of the demotion on this site although I am convinced that incoming links is a major factor in other demotions.
Rather than just deleting the thin pages it would have been better to have increased their size/quality to see if this would have caused the same ranking improvement, I do not see why not although it may have been smarter to simply recreate 10 new pages with richer content rather than increasing the size of existing pages in case the penalty was page rather than site wide.
I was surprised to see the site reappear as I had read here [searchengineland.com ] that Penguin was only ran on occasions and thought that the demotions would be lifted at that point.
I now think that Penguin is ran intermittently as google claim causing the demotions but the penalties can be lifted at any time - perhaps after a good grace period has passed.
The way ahead I am going to increase the quality of the inner pages on other sites where i suspect the same problem and see how this affects these similiar sites if this first step works then fine after that I will try anchor text dilution on the same sites.