Latest update is Google panda #21 in november
Penguin 1: April 24, 2012 (3.1%)
Penguin 2: May 26, 2012 (less than 0.1%)
Penguin 3: Oct. 5, 2012 (0.3% english queries)
Page layout algorithm improvement
As we’ve mentioned previously, we’ve heard complaints from users that if they click on a result and it’s difficult to find the actual content, they aren’t happy with the experience. Rather than scrolling down the page past a slew of ads, users want to see content right away. So sites that don’t have much content “above-the-fold” can be affected by this change. If you click on a website and the part of the website you see first either doesn’t have a lot of visible content above-the-fold or dedicates a large fraction of the site’s initial screen real estate to ads, that’s not a very good user experience. Such sites may not rank as highly going forward.
