Google Pay Tracks Every Purchase — and Feeds It Into Your Ad Profile

Google Pay processes transactions for hundreds of millions of users worldwide, handling everything from in-store tap-to-pay purchases to online checkout flows and peer-to-peer money transfers. Each transaction generates a detailed record — merchant name, amount, location, time, and category — that Google stores and integrates into its broader data ecosystem. For a company whose primary revenue comes from targeted advertising, transaction data represents perhaps the most commercially valuable signal available: proof of what consumers actually buy.

Google's privacy policy allows the company to use transaction data from Google Pay to "personalize your experience across Google products," which includes advertising. When you buy running shoes through Google Pay, that purchase can inform the ads you see on YouTube, in Gmail, and across the millions of websites in Google's advertising network.