Google, Mastercard struck a secret deal to link online ads to offline sales

Google paid Mastercard millions of dollars for the credit card data

For the past year, select Google advertisers have had access to a potent new tool to track whether the ads they ran online led to a sale at a physical store in the US That insight came thanks in part to a stockpile of Mastercard transactions that Google paid for.

But most of the two billion Mastercard holders aren’t aware of this behind-the-scenes tracking. That’s because the companies never told the public about the arrangement. 

Alphabet Inc.’s Google and Mastercard Inc. brokered a business partnership during about four years of negotiations, according to four people with knowledge of the deal, three of