What's the most underrated tactic for reducing customer churn?

Behavioral trigger-based messaging instead of broadcast emails. Most companies blast the same message to everyone and wonder why churn is high. The magic is in mapping specific customer behaviors — or lack thereof — to timely, relevant communications. For example, if a user hasn't logged in for 7 days, send a different message than if they've logged in daily but haven't used a key feature. I reduced churn by 38% at a D2C meal-kit company by rebuilding the entire post-purchase email program around behavioral triggers, plus introducing a win-back sequence that reclaimed 14% of churned subscribers.