Retailers, data brokers and ads, oh my!

February 17, 2025

By Kim Komando

Linda recently called my national radio show with a question that flooded my inbox. Clearly, a lot of you have experienced a similarly eerie moment.

“I was shopping yesterday at Walmart, looking at kitchen knives. I called my friend and told her where I was in the store. I didn’t buy the knives. Today, I received an email advertising the very knives I was looking at! How did that happen? I never looked knives up online.”

I hear you: “Kim, her phone was listening!” The answer isn’t that simple, but I can explain what’s really going on.

Your digital trail

Even if Linda never searched online for knives, her smartphone was busy collecting data. Your phone tracks your location, not just through GPS but also Wi-Fi and Bluetooth signals.

If you’ve connected to a store’s Wi-Fi or walked in with Bluetooth on, Walmart and other retailers can track your movements. They know where you’re standing in the store. They also know you didn’t buy the knives.

Retailers sell this data to ad networks that then work with data brokers to get your email address. Bingo. Linda got an email from the knife company. I bet she starts seeing ads for knives and related items online, too.

But wait, there’s more

Facebook, Instagram, Google and weather apps track your location, even when running in the background. If you’ve granted them location access, they know where you are and later use that data to serve you ads. 

Throw AI into the mix

Odds are, Linda is now going to get email pitches and see ads on social media for new cutlery, charcuterie boards and cooking classes. This is how AI-driven advertising works. It takes one interest (kitchen knives) and expands it into related categories.

How to protect your privacy

📍 Manage location tracking

• Turn off location tracking for retail apps in your phone’s settings.
• Disable Bluetooth and Wi-Fi when not in use.
• Avoid public Wi-Fi, as retailers use it to log your visit.

🛑 Erase your digital breadcrumbs

• Use private browsing or clear cookies on your phone. If you’ve never done that, here are the steps.
• Don’t stay logged into Google, Facebook, Amazon, etc., while shopping.

⚙️ Adjust your ad settings

• Visit Google Ad Settings to turn off ad personalization.
• Update ad preferences on Facebook, Instagram, Amazon and the rest.

📵 Review app permissions

• Turn off microphone access for apps like Facebook and Google.
• Limit background app tracking in your phone’s settings.

It’s a creepy feeling when this sort of thing happens. Remember, this combination of retailers, advertisers and data brokers is trying to get you to spend a buck.