- infra costs sustainably decreases, exponentially;

- user signups almost-sustainably increases, exponentially;

- OpEx may increase, linearly;

- therefore, profit and scale almost-sustainably continues explosion to a rather enormous scale, landing founders with astronomical wealth.

- and this, by the way, is why charging users for actual costs is pointless. Harmful even! We’re offering values, not collecting fees. We’re going for the moon! Forget about gases for cars, we can pay out of the pocket. That’s irrelevant.

This actually worked for decades, hence the free tier. And the first two bullet points stopped working last midnight. And now Houston is working on a solution.