Build and execute customer retention strategies for a solopreneur business. Use when reducing churn, improving customer lifetime value, building loyalty programs, re-engaging inactive users, or creating retention-focused product and communication strategies. Covers churn analysis, retention cohorts, lifecycle marketing, win-back campaigns, and loyalty mechanics. Trigger on "customer retention", "reduce churn", "keep customers", "improve retention", "churn rate", "customer loyalty", "win-back campaign".