Funnel analysis
Funnel analysis tracks how many people make it through each step of a journey, from first touch to the action you care about, and shows where they drop off. A simple SaaS funnel might run: visited site, signed up, activated, paid. At each step you lose some people, so you watch the conversion rate between steps rather than just the top-line numbers.
For a lean founder this is the fastest way to find your biggest leak. If 60% sign up but only 8% activate, the problem is onboarding, not traffic. Fixing the worst step usually beats pouring more visitors in at the top. Build the funnel from real event data, name each step precisely, and compare cohorts over time so you can tell whether a change actually moved the step you were targeting.