The Hook Model
Nir Eyal's four-step framework for building habit-forming products: Trigger, Action, Variable Reward, Investment.
The Hook Model, developed by Nir Eyal, describes how products create habitual use through a four-step loop: Trigger (an external or internal cue that prompts behavior), Action (the user engages with the product), Variable Reward (an unpredictable but satisfying outcome), and Investment (the user puts something into the product, increasing commitment). The model is powerful for retention and engagement but has been criticized for enabling addiction-like behaviors. In JTBDUX, the Hook Model is seen as a tool for the Little Hire (daily re-engagement) rather than the Big Hire (the initial switching decision). It explains stickiness but not switching.