Panda updates are designed to target pages that arenâ€™t necessarily spam but arenâ€™t great quality. This was the first ever penalty that went after â€śthin content,â€ť and the sites that were hit hardest by the first Panda update were content farms (hence why it was originally called the Farmer update), where users could publish dozens of low-quality, keyword stuffed articles that offered little to no real value for the reader. Many publishers would submit the same article to a bunch of these content farms just to get extra links.
Panda is a site wide penalty, which means that if â€śenoughâ€ť (no specific number) pages of your site were flagged for having thin content, your entire site could be penalized. Panda was also intended to stop scrappers (sites that would republish other companyâ€™s content) from outranking the original authorâ€™s content.
The Google Penguin
According to the Google blog, Penguin is an â€śimportant algorithm change targeted at webspam. The change will decrease rankings for sites that we believe are violating Googleâ€™s existing quality guidelines.â€ť Google mentions that typical black hat SEO tactics like keyword stuffing (long considered webspam) would get a site in trouble, but less obvious tactics (link incorporating irrelevant outgoing links into a page of content) would also cause Penguin to flag your site. Says Google,
Sites affected by this change might not be easily recognizable as spamming without deep analysis or expertise, but the common thread is that these sites are doing much more than white hat SEO; we believe they are engaging in webspam tactics to manipulate search engine rankings.
Site owners should be sure to check their Google Webmaster accounts for any messages from Google warning about your past spam activity and a potential penalty. Google says that Penguin has impacted about 3.1% of queries (compared to Panda 1.0â€™s 12%). If you saw major traffic losses between April 24th and April 25th, chances are Penguin is the culprit, even though Panda 3.5 came out around the same time.