From 'Sticky' to 'Sunny': Why My North Star Metric is Now Time Spent Off Screen

Dec 6, 2025 · 3 min read · I started my career by optimizing for addiction. We didn't call it that, of course. We called it "Retention," "Daily Active Users (DAU)," and "Time Spent." We celebrated when users spent 40 minutes a day in our app. We high-fived when they opened it ...