A subscription box, and whether the second month pays for the first.

Before you build it, four documents about it: who else is already selling to a maker with one product and a mailing list, one price you can defend, a money model with every guess labelled, and where the first customers are.

What it checks first, for this one.

1. What comparable boxes charge and, more usefully, what they charge for shipping separately
2. Whether the category is already served by a marketplace that would take the discovery half of the business
3. What the published churn looks like in the categories that talk about it publicly

Does the contribution on month two cover the acquisition cost of month one, or does the box need a third?