Originally designed to deal with sites that have used dubious “black hat” SEO techniques in order to improve rankings, Google Penguin has had far reaching effects, impacting the rankings on thousands and thousands of websites.
Link building practices that where once considered best practice such as exact anchor text links and lots of anchor text on a page are now seen as manipulating the search engines and are damaging to rankings.
Low quality links are also an issue, and as you have no control over who links to you, Google has provided a disavow tool to allow you to report unwanted backlinks that could be damaging your search engine rankings.
Google Penguin has changed how agencies and website owners must approach their SEO. The focus needs to be on quality content – articles, editorials, press releases, blogs etc; the key is to create great content that people will want to read and share, whether it's on their own site or via social media platforms such as G+, Twitter and Facebook.
Google Webmaster central states: "Provide high-quality content on your pages, especially your homepage. This is the single most important thing to do. If your pages contain useful information, their content will attract many visitors and entice webmasters to link to your site."
This is something that Matt Cutts, head of Googles Web Spam team, has been promoting for sometime, but the repercussions did not start to occur until the Google initial Panda update in 2012, gaining momentum with the Penguin updates in 2013.
There is a greater focus on gaining natural links from high authority domains eg. news sites and creating a buzz around your brand via social media networks.
It’s no longer a viable option to just pay your SEO Company a monthly fee and expect results. The client/ agency relationship needs to be symbiotic with website owners contributing to new content and PR opportunities which can be promoted via PR and social media to create buzz and ultimately high quality links to the brand website.