This is my personal summary of the book Hooked.

  • Habits are defined as “behaviors done with little or no conscious thought”.
  • The convergence of access, data and speed is making the world a more habit-forming place.
  • Businesses that create customer habits gain a significant competitive advantage.
  • The Hook Model describes an experience designed to connect the user’s problem to a solution frequently enough to form a habit.
  • The Hook Model has four phases: trigger, action, variable reward, and investment.

The Habit Zone

  • For some businesses, forming habits is a critical component to success, but not every business requires habitual user engagement.
  • When successful, forming strong user habits can have several business benefits including: higher customer lifetime value (CLTV), greater pricing flexibility, supercharged growth, and a sharper competitive edge.
  • Habits cannot form outside the habit zone, where the behavior occurs with enough frequency and perceived utility.
  • Habit-forming products often start as nice-to-haves (vitamins), but once the habit is formed, they become must-haves (painkillers).
  • Habit-forming products alleviate users’ pain by relieving a pronounced itch.
  • Designing habit-forming products is a form of manipulation. Product builders would benefit from a bit of introspection before attempting to hook users to make sure they are building healthy habits, not unhealthy addictions.


  • Triggers cue the user to take action and are the first step in the Hook Model.
  • Triggers come in two types - external and internal.
    • External:
      • Paid triggers
      • Earned triggers (PR work)
      • Relationship triggers (word of mouth)
      • Owned triggers (next-trigger on the platform right after external trigger)
    • Internal
      • Whatever from within the platform that creates engagement and form habits on the long run
  • External triggers tell the user what to do next by placing information within the user’s environment.
  • Internal triggers tell the user what to do next through associations stored in the user’s memory (brain).
  • Negative emotions frequently serve as internal triggers
  • To build a habit-forming product, makers need to understand which user emotions may be tied to internal triggers and know how to leverage external triggers to drive the user to action.
  • Ask “Why” five times until you reach an answer that accurately describe the internal feeling of the user of the product. Remember FOMO (Fear Of Missing Out).


  • B = MAT (Behavior = Motivation, Ability, Trigger)
    • Ability should be simple. Six elements of simplicity
      • Time - how long it takes to complete an action
      • Money - the fiscal cost of taking an action
      • Physical effort - the amount of labor involved in taking the action
      • Brain cycles - the level of mental effort and focus required to take an action
      • Social deviance - how accepted the behavior is by others
      • Non-routine - how much the action matches or disrupts the existing routines
    • Motivation or ability. Which should you increase first? The answer is always ability.
  • Brain Biases
    • The scarcity effect: the appearance of scarcity affects the perception of value (jar with 10 cookies or jar with 2 cookies; Amazon with only 9 left in stock. really?)
    • The framing effect: the mind takes shortcuts informed by our surroundings to make quick and sometimes erroneous judgements (perform music show in subway for 10 bucks, but if it is in a hall, it would cost 100 dollars; tasting the same wine bottle but told different prices from $5 to $90)
    • The anchoring effect: people often anchor to one piece of information when making a decision (sales discount)
    • The endowed progress effect: increase motivation as people believe that they are nearing the goal (car wash service with a punch card of 10 slots (2 punched) or a punch card with 8 slots (zero punched); Remember LinkedIn profile completion ratio starts with something not at zero).
  • The action is the simplest behavior in anticipation of reward.
  • For any behavior to occur, a trigger must be present at the same time as the user has sufficient ability and motivation to take action.
  • To increase the desired behavior, ensure a clear trigger is present; next increase ability by making the action easier to do; finally align with the right motivator.
  • Every behavior is driven by one of three core motivators:
    • Seeking pleasure and avoiding pain
    • Seeking hope and avoiding fear
    • Seeking social acceptance while avoiding social rejection
  • Heuristics are cognitive shortcuts we take to make quick decisions. Product designers can utilize many of the hundreds of heuristics to increase the likelihood of their desired action.

Variable Reward

  • Variable reward is the third phase of the Hook Model, and there are three types of variable rewards: the tribe, the hunt and the self
  • Rewards of the tribe is the search for social rewards fueled by connectedness with other people.
  • Rewards of the hun is the search for material resources and information (Pinterest and slot machines). Remember how ancient humans used to chase the prey until it is tired (because heat cannot get dissipated through fur), then they kill it.
  • Rewards of the self is the search for intrinsic rewards of mastery, competence and completion.
  • When our autonomy is threatened, we feel constrained by our lack of choices and often rebel against doing a new behavior. Psychologists refer to this as reactance. Maintaining a sense of user autonomy is a requirement for repeat engagement.
  • Experiences with finite variability become increasingly predictable with the lose their appeal over time. Experiences that maintain user interest by sustaining variability with use exhibit infinite variability. Remember FarmVille example with finite variability when they introduces CityVille, ..etc.
  • Variable rewards must satisfy users’ needs while leaving them wanting to reengage with the product.


  • The investment phase is the fourth step in the Hook Model.
  • Unlike the action phase, which delivers immediate gratification, the investment phase concerns the anticipation of rewards in the future.
  • Investments in a product create preferences because of our tendency to overvalue our work, be consistent with past behaviors and avoid cognitive dissonance.
  • Investment comes after the variable reward phase, when users are primed to reciprocate.
  • Investments increase the likelihood of users returning by improving the service the more it is used. They enable the accrual of stored value in the form of:
    • Content
    • Data
    • Followers
    • Reputation
    • Skills gained
  • Investments increase the likelihood of users passing through the Hook again by loading the next trigger to start the cycle all over again.

What are you going to do with this?

  • Ask these five questions:
    • What do users really want? What pain is your product relieving? (Internal trigger)
    • What brings users to your service? (External trigger)
    • What is the simplest action users take in anticipation of reward, and how can you simplify your product to make this action easier? (Action)
    • Are users fulfilled by the reward, yet left wanting more? (Variable reward)
    • What “bit of work” do users invest in your product? Does it load the next trigger and store value to improve the product with use? (Investment)
  • We are all in the business of persuasion.
  • To help you, as a designer of habit-forming technology, assess the morality behind how you manipulate users. It is helpful to determine which of the four categories your work fits into.
    • The facilitator (you use - improve people’s lives)
    • The peddler (you don’t use - improve people’s lives)
    • The entertainer (you use - don’t improve people’s lives)
    • The dealer (you don’t use - don’t improve people’s lives)

© 2022. Abdelrahman Hosny. All rights reserved.

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