Experts have already said that this is a gross invasion of privacy, however Google have assured them that the information will be anonymized.
Google will tie individuals' offline credit card data to their online viewing habits to reveal to advertisers exactly what's working as they target people's wallets.
According to independent technology news site Consumerist, attribution is important to businesses because marketing costs money. Businesses are willing to spend some money on advertising and outreach — but only if they see it translate into a return.
In 2014, Google introduced a function that enabled them to see someone's device when they're shopping — this technical addition was called store visit conversions and measured purchases rather than the number of people entering a store.
Currently this system can record up to 5 billion visits, however according to Google, this doesn't go far enough.
The new system will not be able to identify the person, but the identity is attached to your device.
"In the coming months, we'll be rolling out store sales measurement at the device and campaign levels. This will allow you to measure in-store revenue in addition to the store visits delivered by your Search and Shopping ads," Google said.
So if a store has a loyalty program or collects e-mail address, the data can be captured and used to see if advertising works.
Sources have said that the customers' viewing history will remain available in cyberspace, tied to credit card spending, and there is not much that can be done to stop it.