The Industry

Report: Google Tracks What You Buy Offline Using Data from Mastercard

Google reportedly paid MasterCard millions of dollars to track purchases.
Google reportedly paid Mastercard millions of dollars to track purchases.
ALAIN JOCARD/AFP/Getty Images

Google has been quietly providing certain advertisers with access to Mastercard transaction data, allowing them to monitor whether consumers ending up buying products featured in online ads, Bloomberg reported on Thursday.

Over the course of four years, Google hashed out a deal with Mastercard in which it agreed to pay millions of dollars in order to use data from the two billion payment cards it has in circulation. Most Mastercard users are unaware of the arrangement. Google is expected to capture almost 40 percent of the digital ad market in 2018.

Stores Sales Measurement, the feature that was created from this data partnership, essentially makes note of whether a customer logged into a Google account has clicked on an ad for a certain product. The tracking feature also makes a note of whether the customer then uses a Mastercard to buy said product in a brick-and-mortar store within 30 days of interacting with the ad. Google then provides the advertiser with a revenue report on these sales that includes data on the percentage of customers who went through with buying a product after clicking the ad. Neither Google or the advertisers are supposed to have access to information that could identify these customers.

A Mastercard spokesperson sent a statement to Slate, which read, in part:

Regarding the [Bloomberg] article you cited, I’d quickly note that the premise of what was reported is false. The way our network operates, we do not know the individual items that a consumer purchases in any shopping cart—physical or digital. No individual transaction or personal data is provided. That delivers on the expectation of privacy from both consumers and merchants around the world. In processing a transaction, we see the retailer’s name and the total amount of the consumer’s purchase, but not specific items.

Google has been using the Location History feature in Google Maps to notify advertisers whether users ending up visiting a brick-and-mortar store after clicking on a related ad since 2014. This infusion of credit card data would make its consumer-tracking system all the more powerful. Google has claimed that it has access to “approximately 70 percent” of credit and debit cards in the U.S. The company has reportedly approached other credit card companies in an attempt to strike up similar deals, though Bloomberg was not able to determine if anything resulted from those offers. American Express and Visa did not respond to Slate’s inquiries about whether they also had arrangements with Google.

Google sent also sent a statement to Slate:

Before we launched this beta product last year, we built a new, double-blind encryption technology that prevents both Google and our partners from viewing our respective users’ personally identifiable information. We do not have access to any personal information from our partners’ credit and debit cards, nor do we share any personal information with our partners. Google users can opt-out with their Web and App Activity controls, at any time.

While it’s true that users have the ability to opt-out of ad tracking, Bloomberg reports that Google employees have internally argued that there should be a more obvious mechanism for Mastercard customers to switch this feature off.