I had a site which jumped from page 4-5 to top 5 for all keywords. Here are the details:
Age: 4 months [started link building around 4 weeks ago]
Content: just 1 page
Anchor text %: 17% main
Link building method: Tiered GSA Spam + few PBN links
Maybe new sites were not added in the index of penguin or something like that.. not sure.