Terminate ad personalisation
Google uses data it collects about you to offer personalised ads. Part of this is assigning you a personal advertising ID that is used to accumulate data about you. This can be turned off. Apps can be told not to use that ID to build profiles or to show you personalised ads.
Go to Privacy settings -> Ads.
In the screen that appears, Opt out of “Ads Personalization” by turning On the slider. If you leave the slider in the Off position you are telling Google to continue to apply Ads personalisation.
Note: If you disable Ads personalisation you will still be forced to see ads, but they will not be customised for maximum impact on you.
And if you clear your cache, it will automatically turn “Ads Personalization” back on.