NICOLE KOBIE

Google wants to prove its ads work by tracking you everywhere.

Google’s online stalking has moved offline, invading our privacy simply to prove that the ads it splatters all over the web really do work.

We expect to be followed by ads online. Search for an item — let’s say shoes, as I went on a foot-focused shopping spree this month — and click through to a retailer’s site, and those ballet flats will stalk you for weeks afterward, regardless of whether you bought them or not.

John Lewis and other brick-and-mortar stores used to worry we’d browse in person but buy on Amazon, Google is worried about the reverse: that we’ll use the web to find the shoes we want, but head to the shops to try them on and spend our cash where it can’t be easily tracked.

Little wonder it’s worried, as Google makes the bulk of its revenue from ad sales. In the second quarter of 2017, $22 billion of its $26 billion of revenue came from advertising, which it uses to fund other projects, such as self-driving cars and Gmail, without us having to open our wallets.

To prove that online advertising does prompt offline purchases, Google started buying payment card records, with reports suggesting it captures data on 70% of all Americans. Using card data registered to Google profiles and affiliated sites, it can tie your online persona to the card purchasing data it buys, and with that linked data show retailers that you’ve seen an ad for those

shoes online but bought them offline instead. It’s a lot of effort to prove web advertising isn’t useless.

Tech-savvy sort that you surely are, given you read this particular magazine, you’re probably groaning at my whinging – just get an ad blocker, already. Thankfully, in the online world we still have some limited power left and can block advertisements that follow us across the web, nagging us about shoes or whatever other product we once digitally glanced at.

But there’s no opt out for Google’s offline surveillance. You can’t stop it from buying your card data so, short of paying with cash all the time, the only way to prevent the web giant from linking purchases to your account is to not have a Google profile – swap its Search for DuckDuckGo, Vivaldi for Chrome, Bing Maps for Google’s own, and so on. It’s certainly possible, and good luck with it.

That doesn’t help the millions of people without the know-how or time to dodge Google’s reach on the web, so good luck also to privacy advocate EPIC, which has filed a complaint with the FTC, asking the American communications regulator to investigate Google’s offline tracking of in-store splurges.

Google has responded that it doesn’t know the names or other personallyidentifying data from the card records. But for this to work, Google needs to know what ads it shows a user, and connect that with their offline payment card purchases. Google’s database may well identify me via a random series of digits rather than my name, but it knows who I am – or can if it wants to. The company is privy to everything from my location to my typos – I’m writing this in a Google Doc, for crying out loud. Google also claims that it doesn’t pass on our details to its advertisers, who are merely told that a certain percentage of people shown an ad online later shopped at the store offline.

Regardless of Google’s defence, what it adds up to is unprecedented surveillance, costly data gathering, and cutting-edge analytics – all to check if that an ad for shoes led me to buy them.

Don’t only blame Google. We’ve built the web using a precarious business model, and Google has realised that. But rather than find a solution, it’s engineering remarkable ways to artificially hold up this house of cards.

I want driverless cars as much as the next person, and love not paying for Gmail, but rather than spend its time on incredible feats of data engineering, Google needs to find a better way to pay for it all. Put those smarts to use on finding the successor to invasive advertising, not holding up a failed system.