viral - 8:23 am on Oct 9, 2013 (gmt 0)
What I did to achieve this - absolutely nothing. Literally not a darn thing, stopped adding new content, new links, etc. The website was not touched since it got the penalty.
Atlrus that is interesting because I was talking to another SEO friend today and he said that happened for 3 of his sites that he had given up on. He made new sites in the same niches and they were doing well but his old sites came back and overtook his new sites.
His exact words were "I didn't do a #*$! thing". He is happy but also annoyed as he outlayed quite a bit for the new sites.
I guess there might have been a bit of a roll back in this penguin update as others have suggested but as we talked it out he said maybe the sites picked up some links naturally along the way although he can't see them in webmaster tools or in ahrefs.