Google Search could be, until recently, seen as a misunderstood magic – two users in the same country, the same query, but different result. The company was testing personalization, but now it belongs to the past.
Personalized search means that the algorithms of the provider of the concrete search (Google is the most relevant for us) are set to provide the user with the most relevant search results. The relevancy was based on the match of terms and position, but also from the previous search. Basically, from all that the search knows about you.
Before Google became a target of controversy, such as some social sites when personalizing news feeds, the company has announced in later 2018 that the search personalization belongs to the past. The results are no longer personalized. After testing, Google is convinced that the personalization was not efficient nor helping for the users. Another reason is that majority of the users usually precisely identify the thing they are searching for.
What does it mean to you?
For you as an advertiser it is easier to evaluate the success of your ads and content without the search personalization. You just take the ranking into consideration. If Google kept the personalization, it would be difficult for you to consider the SEO optimization and evaluate its successes or failures.
Some algorithms will continue to work
Google algorithms, however, continue to sort the content according to several criteria. The most important of them is the locality, based on which the most relevant results are showed up to the user. The user can change the location of their results easily. Next process of sorting depends on web crawlers, bots which evaluate the content in search. They are considering index, reputation of the webpage where the content was published and the reputation of the author. The lower the reputation of the author (= unknown author) the worse the content evaluation.