A number of years ago, people started to suspect their phones were listening to them. They’d “magically” see ads on Facebook or news websites for products they had barely mentioned in passing. Because our phones are always listening for “wake words” (like “OK Google” or “Hey Siri”), it was natural to grow suspicious that they were monitoring conversations and auctioning off that data to advertisers. The truth is, your phone is not always listening and scanning your conversations for ad triggers. However, countless people have reported seeing ads for things they’ve merely thought about. The reason this predictive advertising happens is fascinating, a little scary, and just a tad reassuring. “I can’t be the only one noticing this” Aakash Gupta writes about AI, tech, product growth, and more. He recently took on the challenge of explaining this freaky concept to a concerned Internet citizen. “I get how the phone can target ads by hearing and seeing me, but how is it showing me ads based on my thoughts? I can’t be the only one noticing this,” an X user wrote. Here’s Gupta’s explanation: It starts with a real-time auction every time you open an app or website that serves ads. “Every time you open a website or app, a real-time bidding auction fires in under 100 milliseconds,” Gupta wrote on X. “Your GPS coordinates, browsing history, device fingerprint, age, gender, income bracket, and hundreds of inferred interest categories get packaged into a ‘bid request’ and broadcast to hundreds of companies simultaneously. One company wins the ad slot. All of them keep the data.” Some estimates put the number of ads the average person sees in a given day between 4,000 and 10,000. In fact, most are almost invisible to us now. That’s why ad companies have to make them hyper-targeted. Gupta explained that your data isn’t only collected when you use a website. Some apps on your phone may pull your location data thousands of times per day, creating a detailed map of pretty much everywhere you go. So how does that lead to “telepathic” advertising? By figuring out what people who are almost exactly like you are interested in buying. “The algorithm doesn’t hear your thoughts. It compares your behavioral fingerprint against millions of similar profiles and predicts your next interest before you’re consciously aware of it,” Gupta wrote. “It makes hundreds of predictions per day. You ignore the misses. The five hits feel like telepathy.” Let me explain exactly why your phone seems to read your thoughts, because the real answer is more invasive than telepathy.Every time you open a website or app, a real-time bidding auction fires in under 100 milliseconds. Your GPS coordinates, browsing history, device… https://t.co/J2YLZkE60V pic.twitter.com/mtL8AQCAlY— Aakash Gupta (@aakashgupta) March 19, 2026 Akash Muni, a software developer, explained it even more simply: “You are not unique. There are 10,000 people with your exact age, location, income bracket, browsing history, purchase pattern and social graph. When those 10,000 people started searching for running shoes, you hadn’t yet. But you will.” He said it’s called “predictive behavior modeling,” and that it has become eerily accurate. Famous case One famous case of this kind of modeling in advertising involved Target sending coupons for baby items to a pregnant teenager’s home. The only problem was that they identified her pregnancy so quickly that her parents didn’t even know yet. The New York Times wrote, “[A Target statistician was] able to identify about 25 products that, when analyzed together, allowed him to assign each shopper a ‘pregnancy prediction’ score. More important, he could also estimate her due date to within a small window, so Target could send coupons timed to very specific stages of her pregnancy.” Similar modeling is used in many ways, not just advertising. Some companies combine data on their employees with known trends and events (like layoffs or changes in HR policies) to predict when someone might quit or leave—even before they do. When it happens on your phone in a fraction of a second, it can be pretty shocking. In fact, the accuracy can be so spooky that some people refuse to believe the modeling is “predictive” at all. “Everyone is saying it just predicts.. now explain if I just happen to think about a random product which doesn’t basically interest me in any shape or form.. for example a conversation I just happened to have like 5 years ago.. and boom!.. here you go, ads flying in right after,” one X user wrote. “Yes, yesterday I was thinking of the cafe I once hoped for, and in the morning the first ad I saw was that cafe’s ad. How is it possible?” wrote another. As Gupta said, predictive modeling is wrong hundreds or thousands of times a day. But we don’t notice those ads for things we’re not interested in because we’re too focused on the ones that are frighteningly accurate. It’s hard to accept that our thoughts and choices aren’t as unique as we’d like to think they are Some people have trouble believing that phones aren’t psychic. Photo credit: Canva It turns out humans are actually pretty predictable. Much of what we do and think is driven by our environment and the systems we live in. Those environments and systems can be tracked and measured with incredible efficiency. If there’s any solace to take in this relentless mining of our data, it’s that the whole system works because there are people out there just like us. There are countless others the same age, with similar family structures, interests, income brackets, and more. In another world, maybe we would all be friends! In the meantime, we can thank them for turning us on to that awesome pair of running shoes we didn’t even know we needed. The post Tech expert explains why you ‘magically’ see ads for things you think about appeared first on Upworthy.