RetainStack is a retention and subscription cockpit for small digital agencies and boutique SaaS tools (MRR $2k–$50k) struggling to track who is likely to churn, which plans are unprofitable, and where to upsell. Today they hack together Stripe exports, Google Sheets, and manual cohort analysis—too complex for non-analyst founders. RetainStack plugs into Stripe, Razorpay, Paddle, and PayPal to auto-build cohort charts, churn alerts, and at-risk customer lists, plus playbook-based email nudges (e.g., usage drop, failed payment, trial about to lapse). It differentiates from generic analytics by going “from charts to actions”: opinionated templates for winback sequences, price-rise rollouts, and customer segmentation tuned for small teams. Revenue is a simple SaaS (e.g., $29–$99/month) with upsell for hands-on retention audits done from India for global customers.