AARRR: Pirate Metrics for the Customer Lifecycle

The AARRR framework, or 'Pirate Metrics,' models startup growth by tracking the customer lifecycle across five stages: Acquisition, Activation, Retention, Referral, and Revenue. It helps teams diagnose funnel leaks by measuring conversion rates between each step, moving beyond simple vanity metrics. For example, you can see if users aren't returning (Retention) or telling friends (Referral). The main footgun is treating it as a linear checklist; it's a loop where strong retention and referral drive new, cheaper acquisition.