Declining Importance of In-Links for Google Page Ranking
Searchmetrics recently investigated the characteristics of pages with high Google rankings and the factors that seem associated with these pages, and found that relevant and high quality content is more important than in-links (or backlinks as described in the article). We discussed the strategy of ranking pages based on the number of links on other websites that lead to a certain page in class, with the intuition that if many other websites point to a given page, there must be valuable or useful information about some topic or keyword contained on it. However, there is an obvious fault with this idea in the real world: companies and corporations are able to take advantage of this system by generating false links to their own pages to increase their own rankings. This study analyzed the top 30 search results for a set of 10,000 relevant keywords, and found some interesting trends and results.
First of all, the correlation between the number of in-links that pages have and their ranking is 0.28, and has been declining since 2013. This means that the value of having many in-links to your page is gradually declining, and rankings are beginning to be based on other factors. Similarly, the domains that included the in-links tended to be different in higher ranking pages than in lower ones. Intuitively, this indicates that if many separate sources link to the same page, it likely has more valuable information than if only a few pages have many links to it, which seems suspicious. To avoid counting the same link on several different pages of a website, such links are only counted once in the survey. Interestingly, it additionally seems that the number of in-links from new sites has become a better indicator of page ranking. So it seems that Google has begun placing higher value on in-links coming from certain known, reputable sources rather than random, unknown sources, which seems to be a logical conclusion that if a well-known source links to a page, the quality of that page is likely high.
Overall, it seems that although the number of backlinks to a page are still important in the page’s ranking, there are other, at times related, factors that are being weighted increasingly heavily in Google page ranking algorithm. This shift is placing an emphasis on useful, high quality content included in a page rather than on the number of (possibly fake) links to it.