Google uses credit-card data to track offline purchases

With the help of tracking scripts, the Internet giant Google is linking the data it collects with credit-card transactions and other information amassed in the real world. It can then share its findings with advertisers, telling them exactly which digital ads lead to actual purchases in online shops or brick-and-mortar stores.

(Bild: Google / iStock)

Björn GreifEditor

Google has taken the next step in the process of creating a completely transparent customer. At its annual marketing conference in San Francisco, the company lifted the curtain on some new analytics tools for advertisers. One of them is able to link all the credit-card transactions made by a user with the online ads that this person happened to click in the past – enabling precise information about which ads ultimately led to the purchase of the product being advertised. In the process, it makes no difference whether the purchase was made in an online shop or in a brick-and-mortar store.

According to Google, it now has access through its partners to 70 percent of all credit- and debit-card transactions in the United States and can use this data to produce more precise figures on the effectiveness of online advertising. If a user previously clicked an ad but did not buy anything online, advertisers couldn’t know whether the ad was a waste of money, because they had no way to determine whether it generated sales in brick-and-mortar stores. But if data collected by the tracking scripts of Google’s advertising network is combined with credit-card information and other data gathered in the real world, including sales in stationary outlets, it can show advertising customers that their ads do indeed work – and this is the precondition for getting them to spend more money for advertising (on Google).

No added value for users

For a long time now, Google has been using location data beamed by smartphones to keep an eye on the stores that users visit, but had no information on whether consumers actually bought anything at those stores. That will change, thanks to the enhanced tracking system with credit- and debit-card data. Google and its advertising customers will now have a much clearer picture of a user’s interests and buying behavior.

“Up to now, Google has provided added value to its users – such as location data for Google Maps services – as the trade-off for more data,” says Marc Al-Hames, the Managing Director of Cliqz. “However, I don’t see any benefit at all for users here. Data is collected and exchanged, but the consumer receives no service or added value for it. This is a flagrant imbalance! It amounts to an even greater violation of our privacy, merely to improve the targeting ability of advertising campaigns.”

Anonymization is not secure

Google emphasizes that no names are attached to the data; it is anonymous. Advertisers only find out, for example, that user A clicked specific ads B in the morning and spent a total of C in a particular store that afternoon. But this kind of anonymization isn’t really secure. A study by the Massachusetts Institute of Technology (MIT) determined that it takes just three anonymized credit-card transactions to discover a customer’s true identity.

Google users can partially block the data collection via their account settings, but they cannot prevent it completely. This is where anti-tracking tools such as those from Ghostery and Cliqz can form a line of defense that will block or modify data transfers to the trackers so that they can no longer tap personal data.

“We need to thwart the ever expanding reach of tracking scripts in online advertising,” says Al-Hames. “If we all use effective anti-tracking tools and correctly apply the data protection settings in our browsers and devices, we can ensure that the business model of online monitoring is deprived of its foundation.”