30-day retention is the headline metric for most consumer products; 12-month retention is the SaaS benchmark.
Net Revenue Retention (NRR) measures retained revenue including expansion. Best-in-class SaaS reports NRR above 120% (existing customers grow even as some churn).
Voice-driven post-purchase NPS calls correlate with higher retention because they create a touchpoint customers remember positively, even when the answer was an 8 not a 10.