SaaS Metrics in the AI Era

The classic SaaS metric stack still holds in 2026, but AI-native cost structures quietly break three of its numbers. When per-token inference cost sits in COGS, gross margin, LTV, and CAC payback can all read wrong unless you re-segment them. The stack did not get longer; it got two new lines and one segmentation discipline.

This cluster covers the metrics that survived, the ones that distort under usage-based cost, the new AI unit-economics measures worth tracking, and ACV-segmented benchmarks you can actually compare against. Contribution margin per customer, inference expense ratios, and the numbers a board reads before anything else.