Any insight on what factors Penguin is looking at?

[AdamThompson]

Anyone have insight into what specific factors penguin is targeting and how it works?

Matt Cutts seemed to infer that the site was targeting things such as spun content, keyword stuffing, etc. but most of the sites that have been hit that I've seen aren't doing any obvious content spamming like that.

For example:

• Is penguin looking primarily at onsite or backlink factors?
• Does Penguin just discount spammy backlinks, or does it apply an additional penalty to sites that have poor quality backlinks?
• Anyone noticing specific onsite or offsite factors that correlate with whether a site has been hit or not?

[Sean_Dawes]

Given the recent warnings in google webmaster tools for some website owners I would say they are looking at your backlink profile for unnatural link profiles with heavy exact match anchor text and links from untrusted sources.

In terms of onsite, footer nav links using exact match, keyword stuffing on page, duplicate content. I feel as if none of this is new news but they are trying to enforce and be more aggressive with how they treat websites on these factors.