The Briefing

CAC payback of 32 months in the $5M–$50M ARR band signals inefficiency that would have drawn alarm in 2021 but now reflects a deliberate recalibration toward durability over blitz-scaling. This briefing examines that shift through Q1 private company benchmarks, where the tension between growth velocity and unit economics remains unresolved, alongside Kellogg's emerging framework for measuring software durability and a technical deep-dive into agentic security systems—a category where AI promises to collapse mean-time-to-response but threatens to expand the attack surface simultaneously. The through-line: capital efficiency is no longer optional theater for Series B decks; it's table stakes. Watch whether payback periods compress in Q2 or whether founders continue trading speed for margin expansion.