Nir Eyal’s Hooked outlines a four-step model—Trigger, Action, Variable Reward, and Investment—designed to build products that create instinctive user habits and unprompted engagement. Habit-forming products offer superior defensibility and higher lifetime value by transforming user actions into lasting routines, which can be evaluated ethically using the Manipulation Matrix. For the full blog post, visit Nir Eyal's website.