Google is tracking users' shopping sprees even at brick-and-mortar shops, aiming to gauge just how successful digital ad campaigns really are.

In a bid to show advertisers that its tools really work, Google aims to bridge the gap between digital and physical retail by keeping an eye on users' offline shopping habits.

Thanks to partnerships with debit and credit card companies, Google can now pair users' online identities with their in-store purchases. Google wants to determine the success of ad campaigns by looking at whether users clicked an ad online before buying the item in a physical retail store.

Google Tracking Offline Shopping

The company notes that mobile has brought the physical and digital worlds closer together, blurring the line between them.

"While most purchases still happen in-store, people are increasingly going on their smartphones to do research beforehand," Google explains.

Back in 2014, Google launched store visits measurements to offer marketers more details about consumers' shopping habits that begin on the internet and end in a store, so that marketers can use that data to deliver better ad experiences. The company has continued to improve those tools and it's using advanced machine learning, as well as mapping experience to enhance its accuracy.

For now, store visits measurements cover Google Search, Shopping and Display, and will soon expand for YouTube TrueView campaigns. However, Google notes that this is just a part of the game, as just measuring store visits won't suffice. While these measurements can provide valuable insight, marketers also need to see if their online ads are translating to real-world sales.

With this in mind, Google will release store sales measurements in the next few months, allowing marketers to measure in-store revenue in addition to the physical retail store visits prompted by online ads.

How It Works

The companies that Google teamed up with reportedly make up a whopping 70 percent of all credit and debit card purchases in the United States, CNN reports. With the new store sales measurements in sight, credit and debit card companies will give Google encrypted data about store purchases. Google can compare that information with the collective profiles of online users who clicked on relevant ads for those products.

Encrypted Data

Since the data sent to Google is encrypted, Google will not be able to access any identifiable payment details such as the person's name or what they purchased. The move just aims to give more insight to advertisers regarding how much physical retail sales their online ads drive, by matching ad clicks with in-store data without getting too personal.

At the same time, this tracking applies only to credit and debit card purchases, not for cash payments.

In other words, if you don't want Google to track your offline shopping spree so it can help advertisers gauge the success of their online ad campaigns, pay in cash.

The fact that companies track people's offline habits is no big surprise, and it's nothing new either. Facebook, for instance, frequently buys third-party data about users' offline behavior so it can serve better targeted ads.