The domain authority of a website tells you how important the website is for your topic. It is a factor that is very likely taken into account in the search engine ranking. After all, one who is considered to have great authority with valuable and trustworthy content should be ranked higher in the SERPs. This way, search engines want to ensure they display relevant and secure content to users.
There are numerous factors that are responsible for a high domain authority. These are, however, not publicized by Google, just like the other ranking factors of the search algorithm. Nonetheless, after comprehensive observations and experiments, search engine experts agree on certain points. Thus, these points should be taken into account:
The longer a website exists, the more authority is possibly attributed to it. Content added over the years and the increasing traffic could, therefore, benefit the ranking since the search engines will presume a higher quality of the information.
The credibility and, hence, authority of a domain can be ranked higher if the domain has multiple backlinks from trusted sources.
Backlinks that point to a domain should originate from different pages. If, for instance, so many links originate from a single page or the same webmaster, the search engine can assume a manipulation. Furthermore, the content relevance between backlinks should also be considered. Many randomly placed links to pages that do not have significant additional information can negatively reflect on the domain authority since these are most likely disadvantageous to the user and could, thus, be considered as spam.
Also important is the time distribution of the links. A natural link collection develops over a long period of time. However, if many backlinks are created within a very short period of time, the search engines may assume the use of Black Hat SEO, for example, through purchased backlinks.
Other possible criteria
There are many other factors that influence the authority of a domain. For instance, websites that integrate blogs, infographics, or videos often enjoy higher authority.
An article by a well-known author with a good online reputation would probably make a website on which the article is published more trustworthy. The search engine evaluates how often the name of the author is searched and, for example, how often his name appears in the press. If an author is mentioned in many blog posts, eBooks, or social media channels, the authority of the author would most likely be improved and would, in turn, translate to a higher authority of the websites on which he is published.
In addition, it is quite possible that reviews on sales and recommendation pages also have an effect on the domain authority.
Whether one considers the concept of domain authority to be fair or not: A domain authority that is ranked as high as possible is certainly essential for good search engine optimization. Here, all related factors could play a role even if, based on a lack of enough official statements from Google, not all experts agree on their weighting.