RankBrain
According to Google's statement, RankBrain is among the most important ranking factors.
So what is RankBrain and why is it so important?
Before RankBrain was developed, it was thought that the positions of the pages ranked on Google were determined by engineers working at Google, but RankBrain's own algorithm optimizes the positions of the pages by taking into account the user click-through rate, bounce rate, page dwell time and pogo-sticking rate.
For example: When "new york" is searched on the SERP: Users usually enter the first page that appears, but if the content on the page is not descriptive, does not appeal to the user and the user cannot business owner database find the subject they are looking for in an impressive way, they immediately exit the page and enter the second page:

If they do not like the content on the second page either, they click on the third page:
Finally, they like the third page and start reading the content. Here, entering the pages and immediately exiting and then returning to the search page is called Pogo Sticking, and this situation is defined as a very important factor for RankBrain. RankBrain detects a page that has a very high bounce rate on Google and is constantly Pogo Sticking the page. In the example above, the page that is in the first place drops to the 2nd or 3rd place, while the page that is in the 3rd place and whose content we like can rise to the first place. Thus, pages measured with factors that are important for user experience are in the top positions.
Factors that RankBrain cares about:
The time the user stays on the page (Dwell Time),
User click-through rate (CTR),
Frequency of returning to the search page (Pogo Sticking),
Bounce Rate.
The Duration the User Stays on the Page (Dwell Time)
According to Google's statement, Dwell Time is of great importance for RankBrain. You can read the related news here . According to Searchmetrics research, the average Dwell Time of the first 10 pages listed on Google is 3 minutes and 10 seconds.