The demo was free. The invoice is not.

An AI feature that costs nothing with one user costs a fortune with a thousand — model the bill before you set the price, not after the first invoice.

On your laptop the feature is free. You're the only one calling it, a few cents trickle by, and nothing about the bill demands your attention. Then you launch: every button click fires a prompt, every page load hits the API, and now a thousand real users are each doing that twenty times a day. Do the arithmetic honestly — at two cents a call, twenty calls a day is forty cents a user, roughly twelve dollars a user a month, and twelve thousand dollars a month once you've got a thousand of them. That's not a rounding error. That's a business that can't pay its own bill.

The tactics for cutting that number — caching, batching, cheaper models for easy tasks — are their own topic. This one is about not getting blindsided in the first place.

Two checks from this doctrine

Real value, not a teaser — two of the 5 checks in full. The rest are in the one-pager.

A feature that's free with one user isn't free — it's just unmeasured. Price it after you know the bill, not before.