Report: Google, Mastercard partnership secretly tracks purchases, raises privacy questions

Some Google advertisers are using a new tool that can track whether ads they ran online resulted in a sale at a physical store in the U.S., Bloomberg news reported. A trove of Mastercard data that Google bought for millions of dollars is, in part, used to make the analysis, according to the report.

Mastercard has about 2 billion card holders, but most of them are unaware about this kind of ad tracking, the report stated. Why? Both companies "never told the public," according to Bloomberg.

How was it arranged?

Alphabet Inc.’s Google and Mastercard Inc. formed a partnership after about four years of negotiations, the report stated. The move is now raising privacy concerns about exactly how much information data technology companies like Google can tap into.

The partnership is apparently one way Google can measure retail spending and boost its business as Amazon and other online companies continue to grow, according to the report.

Consumers may take a different view.

"People don’t expect what they buy physically in a store to be linked to what they are buying online,” Christine Bannan, an attorney with the advocacy group Electronic Privacy Information Center, told Bloomberg. "There’s just far too much burden that companies place on consumers and not enough responsibility being taken by companies to inform users what they’re doing and what rights they have.”

In a statement to Bloomberg, Google told addressed the ads tool but did not the Mastercard partnership:

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.

Can people opt-out?

The company also said consumers can opt out of ad tracking by using Google’s Web and App Activity online console. Some Google employees have complained that the service does not allow an obvious way for cardholders to opt out of the tracking, the report states.

Seth Eisen, a Mastercard spokesman, also did not comment mention the agreement in his response. But he told Bloomberg the company shares “transaction trends” with merchants in order to measure "the effectiveness of their advertising campaigns," according to the report.

Eisen also said the information includes sales volumes and the average size of the purchase. It is only shared via permission of the merchants.

"No individual transaction or personal data is provided," Eisen said in a statement. "We do not provide insights that track, serve up ads to, or even measure ad effectiveness relating to, individual consumers."