Google can link purchases of MasterCard customers to their email addresses and thus use them to track the credit card users’ online activity to see whether online ad campaigns generate offline sales.
Google purportedly has a secret deal with MasterCard that allows the giant search engine to see if the ads it posts online lead to purchases in high street shops, Bloomberg reported citing a number of unnamed sources, the Daily Mail wrote.
According to Bloomberg, under the deal that reportedly took four years to negotiate, if a person uses his or her MasterCard to purchase within 30 days an item whose advert he/she earlier clicked on Google, the technology giant sends a report to the advertiser where transactions made in-store are filed under a column labelled “Offline Revenue.”
Google is also able to track purchases shoppers make at high street retailers when they provide a Gmail email address at the cash register.
For consumers who don't provide an email address, the company relies on third-party companies, like MasterCard, that process card transaction data.
This means that even if a store doesn't have a partnership with Google, other groups who view or process its card transactions may pass customer information on to the search giant.
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A MasterCard spokesperson said that purchased items are never linked to personally identifiable information, including the buyer’s billing address, name, age, or account number.
“The way our network operates, we do not know the individual items that a consumer purchases in any shopping cart – physical or digital,” he said, adding that no individual transaction or personal data is provided, the newspaper wrote.