Google has made several updates in its algorithms through the years and every update is aimed at enhancing the efficiency of website ranking.
This is done by eliminating low quality and spam sites from the search results.
In other words, the updates are meant to give more credit to websites that work hard towards improving their content rather than to those that concentrate only on scaling the SERPs (Search Engine Result Pages).
Panda was essentially designed to de-rank websites that were overly optimized.
The 22nd update of Panda was released on November 22nd 2012. This update affects 0.8 percent of queries that were received in English. Before this, Panda 21 was released on November 5th 2012. It affects 1.1 percent of queries in English and 0.4 percent of worldwide queries.
One of the major updates this year was Panda 20 which was released on October 9th 2012. The update penalizes websites that have excessive number of advertisements, especially in the top half portion of the page, which is an indicator of poor content quality and quantity.
Panda updates come down heavily on websites that offer duplicated content.
It is important to understand that duplicated content is not plagiarized; it is rewritten or reproduced with minor changes in keywords and content, but essentially has nothing new to offer. Content farms also end up being penalized heavily.
So, this makes originality of content extremely important.
Penguin update 3 was launched on October 5th, less than five days before the Panda 20. The update affects 0.3 percent of search queries in English and 0.4 percent queries in other languages. The first update of Penguin was launched on April 24th and it had a major influence on SERPs. The second update, launched on May 25th 2012, tightened the noose on certain sites.
Penguin updates are aimed at improving SEO practices.
Sites that indulge in unethical link programs including link exchange, linking to low quality link directories, obtaining links inorganically and excessive use of anchor texts are penalized and pushed down the ranks.
Essentially, all Penguin updates are meant to put an end to black hat SEO practices. These updates necessitate websites to adopt organic methods of link building and implementing other SEO techniques.
Diversification of keywords and anchor texts has also become crucial.
EMD or Exact Match Domain update was another very significant update.
It was released on September 27th 2012. This update targets low quality sites that offer no useful content, but mint money by selling ad space on their pages.
These website owners buy many domains that contain highly matched keyword phrases and content.
According to sources, Google updates its search algorithm around five hundred times in a year on an average.
But updates have never come faster than they did in 2012.
So, you need to keep in touch with what Google is up to because these updates have a big influence on websites.