The 24^th of April will be remembered by many webmasters who on that day noticed a dramatic traffic downfall by 30-70%. This was caused by the new anti-spam algorithm by Google which was mentioned by Matt Cutts in the official Google Blog for webmasters.

Since then quite a bit of time has passed and statistical data, successful and unsuccessful cases, along with some answers from Google officials began to appear on the Internet. This time also was enough to conduct a collective experiment in which over 100 people took part, submitting over 150 websites for analysis. Please take note that the experiment was conducted by a Russian team involving mostly Russian websites. Therefore some data (like keywords) will be presented in Russian language.

What exactly happened?

We will not go into all the details of the experiment. The only thing to mention is that all the websites were checked manually for suffering from Penguin algorithm change (reports to which we had direct access were thoroughly analyzed), various metrics were checked and statistics for anchor lists was gathered.

As for the content, no strict pattern has been detected. Sites with and without advertisement, with and without contacts page, with large and small SEO-text on the main page were affected by the Google Penguin.

Things get more interesting when it comes to links. A lot of direct entries have been seen in a group of websites who suffered from Penguin (more than 58% of direct entries in anchors). Here is some statistics:

Average numbers for penalized websites:

• 11% links with site URL (http://domain.com/);
• 15% links with brand name as a company name or domain name;
• 58% links with promoted keywords;
• 14% nofollow links from total amount.

Average numbers for benefited websites:

• 22% links with site URL (http://domain.com/);
• 26% links with brand name as a company name or domain name;
• 23% links promoted keywords;
• 30% nofollow links from total amount.

Out of all the methods that were used to get the site from under the filters, only 301 page redirects to another domain were successful (same name but different domain zone). All the websites eventually were “glued” together and returned to their previous positions in SERPs.

It turned out to be impossible to free a website from a filter by manipulating with anchors of the backlinks (at least according to the data available). Possibly, two months is not enough to get the filter lifted automatically. There is only one case in which a website got a filter lifted after a very thorough work with the external links (WMPU.org).

Searching For The Problems

During the course of the experiment it became clear that not all webmasters correctly identified which Google filter was applied to their website. With Penguin Google implemented numerous global changes like: Page Layout Algorithm, Venice, Panda updates, etc. Therefore, it is important to analyze all the data.

To correctly determine the cause of the problem a detailed history of position tracking for multiple search queries is required. During the analysis the dates of Google updates and the drops in standings have to be compared.

For example, the following graph shows that Google Penguin is indeed responsible, but before that algorithm change there were other problems, which means that the filter is composite.

The following graph show a downfall in traffic from Google, but the problem is clearly not the Penguin.

A clear representation of a Google Penguin influence is seen on this graph (drastic drop during 24^th-25^th of April):

A good way to determine the problem is to use Google Analytics – select the dates after the 25^th of April and compare the data with the one that comes before the 24^th of April by checking the keywords reports and select “Traffic Source – Landing Page”. This way we can see which keywords suffered and their respective landing pages.

As practice shows, if a site is losing positions on high-frequency queries or mid-frequency queries for main sections of the website, then the problem is most likely with the backlinks. But if you are losing standing for mid and low-frequency queries then you should look into your content and outgoing links.

Some examples:

1. External links

The statistics show that the website was affected by the Penguin.

Keyword analysis shows that the website lost standings for high-frequency query “работа в минске” (“jobs in minsk”). Therefore, the reason is probably in external backlinks.

Let’s check the anchor list with OpenSiteExplorer:

We can see that first place is taken by the promoted keyword. To clarify that the problem is indeed with this keyword we check anchor lists for competitor websites in the TOP3. What do we see:

As we can see, all these websites have at the top of their lists an anchor with either a direct URL of the site or no anchor at all (image-link).

2. Duplicate content

The website has lost low-frequency traffic.

If we take a look at which queries were affected, we will see:

After checking the website for duplicates in Google, we see that 93% of indexed pages are full or partial duplicates.

WebTracker.com helps us find pages which are in additional index (unimportant for Google). After we analyze and summarize.

3. Outgoing links

Website has lost positions for low-frequency queries, and mostly for the same pages.

By visiting these pages we see that they contain outgoing links unrelated to the website.

Summary

With Penguin Google made another step towards more organic search results, but a lot of good websites felt the consequences. To deal with the Penguin, first of all, read the Google Webmaster’s Guide. Most successful cases, which are reported, point out the improvements to the website. Therefore, if you are planning ahead, then it’s better to focus on improving your website (mainly usability). But you should also take notice of the examples presented above.

Original post in Russian can be found at http://devaka.ru/articles/google-penguin

English translation by: http://seointrust.com/