Google keeps a list of your purchases based on receipts emailed to your Gmail account.
Google says the information is used to provide personalized services, and is not used to serve ads.
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The fact that Google keeps track of information such as search and location history is fairly well-known, considering the widespread popularity of its search engine and navigation app.
But what may be less obvious is the running list that Google keeps of your purchases.
It's unclear exactly how long the company has been logging this information, but the page was noted in a Reddit thread from nine months ago and surfaced again on Friday thanks to a report from CNBC.