The Hidden Cost of "Free" Grocery List Apps

A few weeks ago, I received an email that made my heart sink. It was from a mother of two who wrote to me after trying SmartCart Family: "Francisco, I've been using [popular app name] for free for three years. Were they really selling me?"

The short answer is: yes.

The long answer is what led me to spend the last two weeks reading data brokerage industry reports, privacy policies of 23 different apps (all very long, all very similar), and interviews with former tech advertising employees.

What I discovered kept me up at night for several days.

The Number No One Tells You

Yes, you read that right. One hundred and eighty-seven euros. That is what, on average, your consumer profile is worth per year to marketing and data analysis companies.

It's not a figure I invented. It comes from several independent studies on the data brokerage industry. And when you start to understand what that profile includes, the number starts to make sense.

What Exactly Does That Profile Include?

Sitting at my desk, with a cup of cold coffee, I took notes on everything a "free" grocery list app can know about you:

• What you buy - Every product, every brand, every category.
• When you buy - Days, hours, frequency, patterns.
• Where you buy - Which supermarkets, which neighborhoods, your mobility. They can even know which aisle you are in thanks to geolocation.
• How much you spend - Your real purchasing power, not declared.
• Life changes - Bought diapers? There's a baby. Stopped buying alcohol? Maybe pregnancy. More ready-made food? Time or health issues.
• Your health - Gluten-free, lactose-free, diabetic products, OTC medications.
• Your children - Approximate ages based on product types (baby jars, kids' cereals, school snacks).

I read this out loud to my wife. We fell silent for a few seconds.

"It's like someone is snooping in our shopping cart every week," she said. "And selling photos of it to strangers."

Exactly.

The Business Model No One Explains

Here is where things get interesting. And by "interesting" I mean "disturbing."

I downloaded the privacy policies of the 5 most popular grocery list apps. I printed them out. It was 47 pages in total. I grabbed a yellow highlighter and started marking.

Three hours later, this is what I had learned:

How the Exchange Works

You give them: Full access to your consumption habits. Your location. Your behavior. Your life patterns.

They give you: An app that works. For free.

They sell: Your aggregated (and sometimes not-so-aggregated) profile to:

• Marketing and advertising companies.
• Consumer product manufacturers.
• Supermarket chains (yes, even if it's not "their" app).
• Data brokers who resell it to... basically anyone.
• Market research firms.
• Insurance companies (this one surprised me the most).

And here is the twisted part: technically they aren't stealing from you. You accepted the terms of service. It's all there, in those 47 pages that no one reads.

Legal? Yes.

Ethical? You decide.

A Real Case That Made Me React

While investigating this, I found the case of a very popular discount coupon app (I won't name names). A security researcher discovered that the app was:

• Tracking your location every 15 minutes, even when you weren't using it.
• Accessing your full purchase history (with permission, of course).
• Selling this data to more than 40 different companies.
• Generating profiles so detailed they could predict pregnancies before the woman herself knew.

Read that last part again. They could predict pregnancies before the woman herself knew.

How? Subtle changes in buying patterns. Less caffeine. More folic acid. Certain types of snacks. The algorithm detected it.

I closed my laptop. I went for a walk. I needed air.

Why No One Tells You

During my research, I found something revealing: most articles about "the best grocery list apps" are written by sites that receive affiliate commissions from... the apps themselves.

They aren't going to tell you that you are being tracked. Because they make money when you install the app.

Even "serious" media outlets rarely dig deep into this. Why? Because tech companies are their biggest advertisers. You don't bite the hand that feeds you.

And the apps themselves, of course, tell you. But they bury it in privacy policies written by lawyers to sound as boring as possible. They want you not to read them.

The Vicious Cycle

The model works like this:

• Free app → More users
• More users → More data
• More data → More value to sell
• More value → More venture capital funding
• More funding → More advertising to acquire users
• And start all over again

You are not the customer. You are the inventory.

The Question I Asked Myself

After all this, I sat down with my notepad and wrote a question at the top of the page:

"How much would a family be willing to pay to NOT be tracked?"

I did the math:

• If your data is worth €187/year...
• And an honest app cost €3.99/month (€47.88/year)...
• You would be "earning" almost €140 a year in reclaimed privacy.

Not counting the intangible value: the peace of mind that no one is monetizing every decision you make in the supermarket.

But there was a problem. A big one.

The Privacy Paradox

People say they value their privacy. Polls confirm it: more than 80% say they are "very concerned" about their data.

But those same people install apps that ask for absurd permissions without batting an eye. Because they are free. Because they are convenient. Because "I have nothing to hide."

I did it myself before I started investigating this.

My (Imperfect) Proposal

I'm not going to pretend SmartCart Family is perfect. It isn't. There are still features I want to add. There are things I could do better.

But there is one thing I can promise you with absolute certainty: I will never sell your data. Not because I'm a saint. But because it is impossible to sell what I don't have.

SmartCart works 100% offline. Your lists stay on your phone. I literally don't know what you buy, when, where, or how much you spend. There is no server to hack. There is no database to sell. There is no way to monetize your behavior.

In exchange, I charge you €2.49 a month if you pay annually.

Is it perfect? No. It would be better if it were free.

Is it honest? Completely.

The Deal is Simple

You pay me for the product. I give you the product. The end.

There is no fine print. There is no "future monetization." There is no "we might introduce ads later."

Your money is my business model. Not your data.

What You Should Ask Yourself

Before finishing, I want you to ask yourself these questions about any "free" app you use:

• If it's free, how do they make money?
• What permissions does it ask for that seem unnecessary?
• Have you read its privacy policy? (Seriously, read it).
• Who do they share your data with? (Usually found in the "Third parties" section).
• Can you use the app completely offline?
• If you stopped using it tomorrow, would they delete your data?

If the answers make you uncomfortable, maybe it's time to look for alternatives.

And if you can't find any that convince you, well... you know where to find me.