Build on Free Data, and the Bill Comes in 'Time' Instead of Money

Put an app on top of a free API or open data and ops cost is zero — it feels like heaven. That's how I started, too. Then I shipped, and learned the cost gets billed in 'time,' not money.

In the last few posts I kept coming back to that “convenience-store BOGO deals app.” Today, the trap people underestimate the most — data ops.

Building really is heaven

Deal info, prices, locations — if you can pull the data you need for free from somewhere, building is pure joy. The app fills up with convincing info without costing a cent. You’ll catch yourself thinking, “Why isn’t everyone doing this?”

The answer to that “why” starts the week after launch.

The trap is the updating

A lot of free data falls into one of two buckets. Either automated collection is blocked, or the format changes on you constantly. Either way, the conclusion’s the same — eventually a human has to pull it down, clean it up, and upload it by hand, every week.

While building, you think “I’ll just fill the data in.” Once you ship, it becomes a chore that never ends. Store deals reset weekly, prices keep moving, and information ages the moment you leave it alone.

The real price tag on a free API wasn't $0 — it was a few hours every week.

So the real question is just one

If you’re building an app that runs on data, ask this before you write any code: “Can I pull this data automatically?” That single answer splits heaven from hell.

If you can pull it automatically and reliably, the app mostly runs itself. But if you can’t — launch isn’t a beginning, it’s the start of labor that comes back every week.

You don't fill data once. You feed it for the rest of its life.

The scariest part is the ‘silent collapse’

The genuinely scary thing about manual updates is that one day they just quietly stop. You forget to update, or the data format shifts and your cleanup step slips a little out of line. And then the app shows old info with a perfectly straight face.

No error. The screen’s still pretty. So I don’t notice, and the user walks off with the wrong info. They only catch it much later — “wait, this is last week’s.”

The scariest moment is when the app shows stale info with a straight face.

So here’s what clicked

After living through this, when an app idea hits me, I look at the data before the screens or features. Does this data run on its own, or do I have to feed it every week? If it’s the latter, I count that time into the “ops cost.”

Data isn’t a side branch of an app — it’s the heart. An app whose heart you have to hand-pump every week won’t last, no matter how well you built it.