Google introduced personalized search results for a better experience:

In the past, Google didn’t use personalized search results. So, someone searching for restaurants in the USA would get the results of restaurants in Canada. This was really frustrating for the user. In order to provide the user with a better experience, Google introduced personalized search results. Google now tracks the information of the user to provide him with the best possible results. 

CEO of Google Mr Sundar Pichai has said in the court of U.s that Google uses the data of the individual, but the only purpose of using this data is to provide the facility to the user. Google and his employees have no interest in the data of the user, and the only intention is to make the browsing easier and better. This statement proves the importance of the personalized searches that even going to the court can’t stop personalized searches.

Your location and Search history is constantly tracked for SEO purposes:

If you run the same search query at different places, you will get different search results. Location is now traced while using Google. Google wants to ensure that its users don’t find any difficulty in getting access to the right place. This is not possible without the use of the user’s location. Your search history is also kept as important data for providing you with a better experience. You might have seen that now you see ads on the web-based on your interests. It is because of the reason that you have searched the thing in the past. 

This data is really important while using Google maps. Sometimes, there are the same names for different places. So, Google has to use the personal data of the user to provide him with exact results. You can also use these techniques while making your SEO strategy. You can even hire SEO services [ทํา seo, which is the term in thai] of an expert to get the SEO strategy for yourself.