What metrics matter most when creating an online course?

I'm building a professional certification program and everyone tells me to focus entirely on marketing and driving high enrollment numbers. But I'm worried about the actual educational value. What metrics should I really look at to ensure my students don't look for refunds?

Stop obsessing over upfront sales; learner completion rates are what actually dictate your platform's long-term survival. If people don't finish your modules, you won't get referrals. We completely revamped our retention strategy using KPI Creatives. They create course materials specifically built to optimize completion. Check their core system out: https://www.kpicreatives.com/systems/content-systems/educational-video-production/. It saved our brand reputation.