If you recently purchased something from a traditional store, you may notice the Facebook ads that you see are associated with that store or product you have purchased.

This phenomenon that most users complain about is not a coincidence. Through its partnerships with retailers, Facebook learns what users are buying either online or through stores. This data is eventually used to target ads to people, based on what they might spend on them.

Any business can send Facebook information about customers, including email, name or phone number, and record what they have bought. Facebook matches this information to user profiles, allowing business people to target these people directly with ads.

A group of large Facebook advertising customers use this information, for example Macy's Macy's and Dex Sporting Goods.

It is known that advertising funds constitute the lion's share of Facebook revenue, which reached $ 17.6 billion in the third quarter of 2019, when 17.3 billion came from advertisements. What makes Facebook attractive to advertisers is the accurate demographic information about the users it provides, and it is published through tools that allow highly targeted ads.

Any business can send Facebook information about customers including email, name or phone number and record what they bought (French)

Our targeting steps:
Business Insider asked Facebook to explain a mechanism that identifies people with offline purchases. Here's how and how to unsubscribe.

The process begins when you buy something, either online or in a store. The retailer may keep information about you from the purchase.

- If the retailer wants to target these customers through Facebook ads, he can send Facebook details about what was purchased, along with the information that could match this purchase to a Facebook profile.

- Personal information sent by the company can include your name, email, phone, or date of birth.

- Facebook only needs a few data points from retailers to create a "custom audience" or group of users whom it identifies as shopping from this retailer.

According to a study published earlier this year, algorithms are able to identify people with confidence based on a few anonymous data points, and a few companies have a lot of user data like Facebook.

- Dividing all identifying information before sending it from retailers to Facebook and then deleting it after using it to match the user to the purchase, according to a company spokesperson.

Data segmentation is a common data privacy practice that converts plain text data into code that can only be read by an algorithm.

- After deleting the retail data, the match remains, i.e. Facebook used the information from the retailers to match the user profiles specified with this business.

From there, retailers can purchase Facebook ads that will be displayed directly on a "custom audience" for their corresponding users, and many retailers use these advertising tools.

"Through store visits to a dedicated audience, we re-engage customers who visited one of our stores with a targeted Facebook ad, and using an audience similar to its shape, created from people similar to those who visited our store, opened up a wider audience of new customers even We can reach sales and increased sales. "

Someone mentioned that retail stores have used Facebook ads to increase their in-store sales.

"We were encouraged by the positive results we saw in the store, and we are excited to continue testing Facebook's offline toolkit to boost our growth," he said.

Facebook only needs a few data points from retailers to create a "custom audience" that identifies them as shopping from this retailer (Reuters)

How can I cancel this feature?
Users can unsubscribe from the "ads based on offline events" service by going to their Facebook settings, choosing "ads" and disallowing "ads based on data from partners".

Facebook also provides a tool to allow people to check if the ad is specifically targeting them. To use the tool, select "Why am I seeing this ad?" From the drop-down menu in the top right of the ad.