Strategic Summary for SaaS Leaders: Between $10M and $30M ARR, B2B SaaS companies experience a structural shift in growth dynamics. While early-stage growth is driven by new customer acquisition, later-stage growth becomes increasingly dependent on expansion revenue—yet most companies lack the internal systems to capture it. This article proposes a system-level framework for designing expansion-driven revenue engines. When B2B SaaS Growth Slowsdows and Stops Adding Up There i