Google Penguin Recovery Services is a series of Google search engine algorithm changes that aim to improve the quality of search results and reduce the impact of certain types of SEO tactics. Penguin algorithmically correlates and discounts the value for certain types of backlinks that Google has found to be unnatural. Unfortunately, sometimes, the activities of previous marketing vendors or the legacy impact of dated SEO practices can cause high-quality websites and online brands to lose traffic because of these updates.
Link building is one of the major SEO strategies. It involves getting back links to your own website from other websites. While earlier the quantity of the back links mattered a lot for page ranking and traffic, with the introduction of Google Penguin update, the quality of the links mattered more. So, websites that had low-quality links lost a lot of traffic while those with good quality links found a big jump in their website traffic.
Apart from link building, black-hat on-page and off-page optimization strategies can also cause havoc on your rankings. Improper header text, meta tags, alt text, URL, etc. are not Penguin friendly. Also, Google is likely to penalize websites that indulge in too much of optimization.