Google Penguin 2.0 Causalities & Reasons Why Sites Got Hit

Google Penguin 2.0 went deeper and had impact in certain small areas very effectively. This Penguin update is a brand new generation of algorithms and has serious effects on web spam.

Does Google Penguin 2.0 Go Deeper on Spammy Links?

Following are Google Penguin 1.0 analysis and issues which resulted in losing traffic and rankings of sites:
If exact match anchor text was used for paid text links.
If there is any spam comments present.
In case if there are any Guest posts on questionable sites.
Article marketing sites.
If there are any links present from dangerous sites.
In this Penguin update Google looked more in to links to other pages apart from links to home page. After Penguin 2.0 update, some of the 13 sites which lost traffic and rankings were examined with more concentration on content and link profiles. There was a point that all these 13 sites uses exact match anchor text heavily and links were aimed at inner pages rather than home page.

Google Penguin 1.0 and 2.0 targets unnatural link profiles and only difference is that penguin 2.0 targets even internal pages rather than just home page.

Google Penguin 2.0 Case Studies:

Two major tools Sistrix and Searchmetrics both have put lists of sites that were affected with Penguin 2.0. Link research tools have taken couple of sites that were affected by Penguin 2.0. Two of these which were analyzed are HOME24.DE and cheapoair.com. These sites have massive drops in search visibility. These both sites have high exact match anchor text keywords and as per Google they are spam sites. But these sites are affected highly than their competitors in their link profiles in various ways due to high usage of exact match anchor text. It is better to remove high number of unnatural links if present in the site before they are disavowed.
Penguin 2.0 is not a manual penalty but it is an algorithmic update. There are still some changes which are to be improved before our site gets penalized.