Link Metrics Remains key to Google Rankings
Link metrics have always remained the most important part in Google algorithm. The concept of Google algorithm was mainly based on link metrics and it continues to be a major factor that effects ranking. A lot of changes has been made to the link building guidelines through the years as more and more people have tried various steps to exploit this metric for ranking better in search engines. The number of changes to guidelines is almost endless with Google actively changing them to close one loophole after another that could provide a particular website unfair advantage over others.
How PageRank works
In terms of ranking a page regarding link authority Google has given importance to both the number of links to a website and also the authority of the website that links to a particular website. Authority means the quality of the link that links back to a particular web page.
For example a website called A might have 10 backlinks from other websites and will have a good ranking in search engines because of the link system. Another website having just one link to the website A will rank better that a website with more links just because of the good authority the website A holds.
Issues with Google Metrics
The problem with the importance Google gives to link building is the number of websites that have tried to exploit this metric. Webmasters have tried to create so many methods to create links on other websites through third party website and various black hat methods. These links in the end do follow the guideline set by Google but have been created unnaturally just for the sake of showing Google crawlers their authority with the number of backlinks they have acquired.
Inspite of thes drawbacks link building still remains an important criteria for search engine rankings.