“We tried to have one or two max for every product. If you have like seven then you're creating noise and the actual signal is getting lost. Think about like the one or two key things — for RoboKiller it was actually less about what was the user doing, it was more about are they actually getting spam calls and are we blocking calls on their behalf.”

Track one or two core engagement metrics per app — seven metrics create noise that buries the signal

Falzon explains that the right engagement metric is not always a user action — for RoboKiller, the product value was delivered passively so the metric was passive too: are calls being blocked, and were any legitimate calls blocked by mistake. The second question (false positives) was the leading churn indicator: when RoboKiller incorrectly blocked a real call, that user churned at high rates. Identifying the one or two metrics that actually predict revenue retention is harder than picking common vanity metrics, but far more predictive.