Backlinks, back-references, or inbound links, refer from a linking website to a link receiving website. 

A high number of incoming inbound links can give search engines such as Google indications of the trustworthiness and popularity of a website. At the same time, backlinks were bought in abundance from untrustworthy websites to influence the ranking of a website artificially.

Link building can indeed be operated in this way - but it is sometimes harmful to your own and the other website! 

A high number of backlinks alone does not say anything about whether they positively influence the ranking in Google. 

Backlink Quality 

Links are a form of editorial recommendation. If company A describes the excellent cooperation with company B in a news article, this is a clear recommendation both linguistically and SEO-technically. Provided a link to company B has been set. 

A directory page that links to tens of thousands of company websites is more likely to deny the editorial recommendation by linking. 

Therefore, Google and other search engines must assess the quality of the link. Only then does it become clear whether the page received from the link has relevant content to offer - or, above all, is being pushed by spam and purchased content. 

Since the Penguin update, Google has been using link attributes to assess the quality of backlinks better. 

Website operators can choose from the following options: 

  • "Nofollow" 
  • "Sponsored" 
  • "UGC" (user-generated content) 
  • No attribute markup 

The attributes can be combined if there are several factors for classification. 

"Good" Backlinks 

Valuable, so helpful backlinks for ranking the link receiving website 

  • Come from trusted, established websites. 
  • Move on the same topic. 
  • Contain relevant, topic-related anchor texts, for example, "original sticker printing".
  • Use keyword sets that match the content and theme of the website. 

Good backlinks are usually awarded based on good content. They are the logical reading recommendation for the users on the other side and, in the best case, refer to additional high-quality content on the Internet.