MHes - 7:16 pm on Nov 23, 2012 (gmt 0)
I hope this may be of interest...........
UK based site started in 2003. Very quiet site in competitive niche until it was worked on 15 months ago. It went from 100 pages and 300 uniques per day to 1.5 million pages and 11000 uniques per day over the last year. All traffic from google organic.
Never shown any problems with any updates etc etc until friday. Now dropped 25%.
The site is very simple. Content is pulled in everyday, from 2 advertisers. These ads make up 90% of each page, but the ads also appear on many other sites. If you click an ad, they all point to one of two sites!
So the problem is that around 20 million links out point to two sites. The other major problem is content is duplicated all over the web.
And I have never been hit until now........