The early work on scurvy gave us the foundational tools. But instead of providing citrus and measuring for malnutrition, tech companies can reason by analogy: create user cohorts by levels of engagement, and analyze what differentiates high value users from lower value ones. These start out as correlations, so use A/B testing to prove causality—once the best levers are found, test many variations of these ideas. Rinse and repeat,
How to identify correlation and then causation in engagement
