Amazon Knows What You'll Buy Before You Do. The Algorithm Scared Me.

Last month, I needed a new laptop charger. Mine died on a Tuesday morning.

I opened Amazon, typed "HP laptop charger," and there it was. Top result. Exact model. Prime shipping.

Normal, right?

Then I noticed something weird. That exact charger had been sitting in my "Recommended for You" section for three weeks. I checked my email. Amazon sent me a promotional email about that specific charger 18 days before mine broke.

How did they know?

Amazon's recommendation engine, known internally as the A10 algorithm, processes over 35 different data points every time you visit the site. It tracks your browsing history, how long you look at products, what you add to your cart but don't buy, and even what time of day you shop.​

But it goes deeper.

The algorithm also analyzes aggregate behavior from millions of other users with similar patterns to yours. If people who bought the same items as you three months ago are now buying laptop chargers, the system flags that you'll probably need one soon too.​

In 2021, Amazon revealed that its machine learning forecasting models can predict demand for millions of products globally in seconds. The accuracy improvement was so dramatic that human forecasters couldn't compete. By 2024, the system delivered a 15-fold improvement in forecast accuracy compared to older models.​

Here's where it gets unsettling.

In 2013, Amazon was granted a patent for something called "anticipatory shipping." The concept is simple but eerie: ship products to customers before they order them.​

The system works by packaging items the algorithm predicts you'll buy and moving them to a warehouse or delivery truck near your location. When you finally click "purchase," the item is already in your neighborhood, ready for same-day delivery.​

Amazon claims this approach reduces delivery times and improves customer satisfaction. But it also means the company is so confident in its predictions that it's willing to move inventory based purely on what it thinks you'll want, not what you've asked for.​

The patent specifically mentions using browsing behavior, cart additions, wish lists, and even how long your mouse hovers over certain products as signals. Combined with your location data and historical purchase patterns, the system builds a probability model of your future buying decisions.

Amazon's 2025 algorithm uses AI-powered contextual understanding, not just keyword matching. It doesn't need you to search for "laptop charger." It knows your current charger is two years old based on your purchase history. It sees you browsing laptop bags and external monitors. It detects patterns that suggest you're upgrading your setup.​

The algorithm also tracks seasonality and trends. If it's November and you bought winter coats the last three years in early December, those coats will start appearing in your recommendations by mid-November, even if you haven't thought about them yet.​

User behavior data collected through cookies includes your session length, likes, and even items you looked at but didn't click. Every action feeds the system. Every hesitation is data. Every abandoned cart teaches it something new.​

Amazon isn't doing anything illegal. You agreed to all of this when you clicked "I accept" on their terms of service.​

But that doesn't make it less invasive.

The algorithm knows when you're likely to replace household items, upgrade electronics, or start a new hobby based on patterns you don't even recognize in yourself. It shapes what you see, when you see it, and how much you're willing to pay for it.​

Some of this is convenient. Predictive recommendations save time. Fast shipping is useful.

But there's a cost. The more accurate the predictions become, the more your purchasing decisions are influenced by an algorithm designed to maximize Amazon's revenue, not your actual needs.​

You can't fully opt out of Amazon's tracking if you use the platform. But you can reduce how much data you give them:

Clear your browsing history regularly. Go to "Browsing History" in your account settings and delete it. This resets some of the algorithm's context.​

Turn off personalized recommendations. In your account privacy settings, disable "Personalized Advertising Preferences." This limits some data collection.​

Use private browsing. Shop in incognito mode to prevent cookies from tracking your session across visits.​

Pause before you buy. If something appears in your recommendations, ask yourself: did I actually need this, or did Amazon just convince me I do?

Amazon's algorithm is one of the most sophisticated predictive systems ever built. It's accurate, fast, and constantly learning.​

That's impressive. It's also unsettling.

Because the better it gets at predicting what you'll buy, the less you're making independent purchasing decisions and the more you're following a script the algorithm wrote for you.​

I'm not deleting my Amazon account. But I'm a lot more aware of when I'm being guided versus when I'm actually choosing.

And that awareness matters.

See you next time,
Better Every Day