In April 2012 Google has started to introduce a new algorithm, called Penguin. Many sites suddenly lost their positions. Google's policy of links counting has been changed. So my question is: what are the new rules, what exactly has been changed in new algorithm? Please answer especially people, whose sites went down in April and they got back all traffic successfully - what have you done and what are your insights? Please only substantive answers. I would like to make this thread a summary to disclose the new changes in the Google algorithm.
The answer is that no one knows for sure, however Google Webmaster Tools accounts now give a hint. In the section that lists all the sites that link to you rather than just displaying the volume of links it also talks about the number of unique domains that these links have come from. I've heard a number of reputable commentators talking about the fact that it's not just HOW many links you have but since Penguin was introduced it's also about the number of DIFFERENT domains that your links come from. I suppose this prevents a situation where you might have 1 million backlinks from one single site.
Google may expect to improve the overall quality of websites using Panda and Penguin updates, it encourage webmasters to avoid duplicated content + unnatural or blackhat link building methods.
Not sure. I have really high quality sites with very good, unique content and I used only white SEO, but they hurt very much.