Nir Eyal’s Hooked: How to Build Habit-Forming Products is a practical guide for creating life-changing products. It breaks down how companies can design services that become part of people’s daily routines, like checking social media when bored or searching Google for quick answers. Nir's main idea is that the first solution that pops into a user’s mind wins. No doubt, Stepehen Anderson rightly said about this book :
“You’ll read this. Then you’ll hope your competition isn’t reading this. It’s that good”
Below is a summary of the book’s key points:
Why Habits Matter for Businesses
Nir defined habits as behaviour done with little or no conscious thought. Habits are powerful because they drive people to use a product without needing ads or reminders. When users form a habit, they automatically turn to the product during routine moments, like opening an app while waiting in line. This type of engagement saves companies money on marketing and builds loyalty. However not every business needs habits. For example, life insurance doesn’t require daily use, but apps like Twitter/X or Amazon thrive on it. Habit-forming products boost customer lifetime value and give businesses a competitive edge.
The Hook Model
Nir introduces the Hook Model, a four-step process to build habits:
Trigger,
Action,
Variable Reward, and
Investment.
Each step nudges users to keep using the product. Let’s understand each step.
1. Trigger
Triggers prompt users to act. There are two types of triggers - External and Internal. External triggers are cues in the environment, like a notification or an ad. Internal triggers are emotions, like boredom or loneliness, that drive users to the product without thinking. For example, feeling lonely might lead someone to scroll Instagram or other social media app. Nir stresses that negative emotions often act as internal triggers, and successful products tie themselves to these feelings.
2. Action
The action is the simple step users take, like clicking a button or searching. Nir builds on Dr. B.J. Fogg’s Behavior Model, which says behavior happens when a trigger, motivation, and ability align. He gives a formula:
Behaviour = Motivation x Trigger x Ability
To make actions more likely, focus on ability first by simplifying the task. For instance, a one-tap login is easier than typing a password. Motivation (like seeking pleasure or avoiding pain) is harder to boost, so making the product easy to use is key. And then triggers in the form of external or internal means will lead to desired behaviour. We can imagine feeling hungry after intense office work and then suddenly Food delivery App notifications came “ Hungry Kya” leading to instant order of sumptuous meals.
3. Variable Reward
Rewards keep users hooked, but they must be unpredictable to stay engaging. Nir describes three types of variable rewards:
Tribe: Social rewards, like likes or comments, that come from connecting with others.
Hunt: Material or informational rewards, like finding a deal or new content.
Self: Personal satisfaction from mastery or completing tasks, like leveling up in a game.
Variable rewards work because humans crave novelty. Predictable experiences get boring, but surprises—like a new post or an unexpected deal—keep users curious. It is similar to Power Law where there is disconnect between outcome and efforts thereby keeping people hooked. This explains why people gamble, participate in KBC (Kaun Banega Crorepati) shows or even prepare for competitive exams as the reward is substantial and variable.
4. Investment
The final step asks users to put effort into the product, like following accounts or saving preferences. Unlike actions, investments aren’t about instant rewards but future value. For example, following someone on Twitter/X doesn’t give immediate gratification, but it makes the app more useful later. Investments create a sense of ownership and make users more likely to return. Nir explains that people value products they’ve invested in, similar to how they cherish friendships they’ve worked on.
Habits as a Strategy
Nir shows how companies like Amazon use habits strategically. Amazon lets users compare prices, even if it means losing a sale, because it builds trust and makes Amazon the go-to place for shopping. This high perceived utility turns occasional actions into habits, even if they don’t happen daily. Some insurance companies also use a similar tactic by showing competitors’ prices, boosting loyalty and sales.
Simplicity and User Autonomy
To make actions stick, Nir emphasizes simplicity. He lists six factors that make tasks harder:
Time,
money,
physical effort,
mental effort,
social norms, and
unfamiliarity.
Designers should remove these barriers to make the product feel effortless. However, Nir warns that users need to feel in control. If a product feels too pushy, users resist—a reaction called reactance. Variable rewards must also balance surprise with satisfaction, so users stay engaged without feeling manipulated.
Ethical Considerations
Nir encourages designers to reflect on their intentions. He categorizes them into four types:
Facilitators use their product and believe it improves lives (most likely to succeed).
Peddlers don’t use the product but think it helps users (risk hubris).
Entertainers use the product but don’t see it as life-improving (may lack lasting impact).
Dealers neither use nor believe in the product (least likely to succeed, often unethical).
Designers should aim to be facilitators, creating products that genuinely help users while being mindful of manipulation. We can also apply the same philosophy in life to be a better person. We have to believe that my efforts will not only reward me but also improve people's lives.
Testing and Improving Habits
At last Nir provided a Habit Testing framework to improve products. First, analyze data to find habitual users. Then, study their behavior to understand what makes the product sticky. Finally, tweak the product to guide more users toward those habits. Observing your own behavior or spotting emerging trends can also spark ideas for new habit-forming products.
Conclusion
Hooked is a clear, actionable guide for building products that become part of users’ lives. It shows how habits save companies money and create loyal customers. The Hook Model—Trigger, Action, Variable Reward, Investment—offers a roadmap to design engaging experiences. Whether you’re a startup founder or a product manager or a person who wants to improve his knowledge, this book provides tools to craft products that hooks, as long as you prioritize simplicity, novelty, and user trust.
Happy Reading !