The metric that actually predicts whether a startup survives isn't the one most founders are watching.
I've had some version of this conversation with a few founders this year. MRR looks fine, CAC is going down, growth numbers look good on a chart.
Then you pull 12-month retention and it's a disaster.
The math that made it click for me: 5% monthly churn means you replace your entire customer base every 20 months just to stay flat. Not to grow. Every dollar you spend on acquisition is basically filling a leaky bucket.
The metric I care more about now is net revenue retention. If your existing customers are expanding faster than churning, NRR goes above 100% and you can theoretically grow with zero new acquisition. Best companies run above 120%. Below 80% and you're running to stand still.
The part founders miss: most of the damage happens in the first 30 days. Users who don't reach some version of the activation moment in that window rarely come back. But you don't see it in aggregate monthly numbers, so it's easy to ignore until it's already a big problem.
Did a short brief on the actual mechanics of this:
https://livebrief.app/p/the-one-metric-that-predicts-startup-death-mp1h2vor
Curious what your monthly churn looks like and when you started paying serious attention to it. For us it was honestly later than it should have been.