Hooked: The Habit Loop
by Nir Eyal · read the original
A distillation of Nir Eyal's Hooked: the four-step loop (trigger, action, variable reward, investment) that turns products into habits, when habit-building actually applies, and the ethics test for whether you should build one at all. A teaching aid; the book has the full research and examples.
- 1
The Hook Model in One Loop
Habits are built by repeated passes through a four-step loop: trigger, action, variable reward, investment. Each cycle tightens the link between a user's need and your product.
- 2
Triggers: From External to Internal
External triggers (notifications, ads) start the loop, but the goal is internal triggers: the product becomes the automatic answer to an emotion, usually a mildly negative one like boredom or FOMO.
- 3
Action: B = MAT
Behavior = Motivation + Ability + Trigger, and ability is the lever that scales. Make the intended action so easy that even weak motivation is enough.
- 4
Variable Rewards: Tribe, Hunt, Self
Craving comes from variability. Design rewards of the tribe (social), the hunt (material and information), and the self (mastery), and layer more than one when you can.
- 5
Investment: Storing Value, Loading the Trigger
End each loop by getting the user to deposit something: data, content, followers, reputation. Stored value makes leaving costly, and the investment itself loads the next trigger.
- 6
The Habit Zone: Frequency Times Utility
Habits need frequency: roughly weekly use or better. Low-frequency products must win on outsized utility instead, and no amount of hook design compensates for a use case that's rare.
- 7
The Manipulation Matrix
Before building a hook, ask: would I use it, and does it improve users' lives? Build as a facilitator. The same loop powers both fitness apps and slot machines; the difference is you.
- 8
Reading Hooks in the Wild
Diagnose any product, including yours, by walking the four steps. Retention problems are usually one specific missing step in the loop, most often the investment.