Which three numbers go on a weekly dashboard for a product with 40 users?

At eleven payers every rate you compute is one person expressed as a percentage, so stop computing rates and start counting events. What I kept at that size: number of accounts that did the core action this week, number of new accounts that reached it within seven days, and revenue that renewed rather than churn percentage - all counts, all things you could read off a list of names. The fourth thing on my board was not a metric at all, it was how many customer conversations I had that week, and it predicted the others better than anything automated.

Mild disagreement with the whole exercise. At eleven paying customers, revenue is the only number that is not a proxy for something you could learn by ringing someone. I would drop the dashboard entirely for a quarter, keep a list of the eleven names, and write one line next to each every Friday about whether they are getting value. You will know more than any three metrics would tell you.

Weekly active accounts, revenue, and a written note of why anyone left. Everything else at forty users is decoration with a chart on it.

I ran a proper dashboard and a plain text weekly note side by side for two quarters. The dashboard was better for spotting a broken signup flow within a day. The note was better at literally everything else, because writing a sentence about why a number moved forces you to know, and a chart lets you nod at it. I kept both and the note is the one I read.

I built a fourteen chart dashboard at roughly your size, spent about two weeks on it, and it never once changed a decision. What did change decisions was a query that listed accounts with no activity in ten days, which I ran manually on Mondays. Build the list, not the chart.