Google saves years of information on purchases you’ve made, even outside Google, and pulls this information from Gmail. It’s complicated to delete this private information, and options to turn it off are hidden in privacy settings. Google says it doesn’t use this information to sell you ads. A page called “Purchases ” shows an accurate list of many — though not all — of the things bought. These purchases need not directly through Google. But because the digital receipts went to Gmail account, Google has a list of info about buying habits.
— source cnbc.com | May 17 2019