The Hook Model


  1. Trigger
    A trigger is the actuator of behavior, the spark plug in the engine. Triggers come in two types: external and internal. Habit-forming products start by alerting users with external triggers like an email, a website link, or the app icon on the phone.
  2. Action
    Following the trigger comes the action: the behavior is done in anticipation of reward. Companies leverage two basic pulleys of human behavior to increase the likelihood of an action occurring: the ease of performing an action and the psychological motivation to do it.
  3. Variable Reward
    What distinguishes the Hook Model from a plain vanilla feedback loop is the Hook's ability to create a craving. Feedback loops are all around us, but predictable ones don't create desire. Variable rewards are one of the most powerful tools companies implement to hook users.
    Research shows that levels of the neurotransmitter dopamine surge when the brain is expecting a reward. Introducing variability multiplies the effect, creating a focused state, which suppresses the areas of the brain associated with judgment and reason while activating the parts associated with wanting and desire.
    The exciting juxtaposition of relevant and irrelevant, tantalizing and plain, beautiful and common, sets her brain's dopamine system aflutter with the promise of reward.
  4. Investment
    The investment occurs when the user puts something into the product or service such as time, data, effort, social capital, or money.
    The investment implies an action that improves the service for the next go-around. Inviting friends, stating preferences, building virtual assets, and learning to use new features are all investments users make to improve their experience. These commitments can be leveraged to make the trigger more engaging, the action easier, and the reward more exciting with every pass through the Hook cycle.
  • 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

Habits are one of the ways the brain learns complex behaviors. Neuroscientists believe habits give us the ability to focus our attention on other things by storing automatic responses in the basal ganglia, an area of the brain associated with involuntary actions.

Habits form when the brain takes a shortcut and stops actively deliberating over what to do next. The brain quickly learns to codify behaviors that provide a solution to whatever situation it encounters.

Increasing customer lifetime value

Fostering consumer habits is an effective way to increase the value of a company by driving higher customer lifetime value (CLTV): the amount of money made from the customer before that person switches to a competitor, stops using the product, or dies. User habits increase how long and how frequently customers use a product resulting in higher CLTV.

Super-changing Growth

A user who continuously finds value in a product is more likely to tell their friends about it. Frequent change usage creates more opportunities to encourage people to invite their friends, broadcast content, and share through word of mouth. Hooked users become brand evangelists - megaphones for your company, bringing in new users at little or no cost.

Products with higher user engagement also have the potential to grow faster than their rivals.

Viral cycle time is the amount of time it takes a user to invite another user, and it can have a massive impact.

More daily active users mean more people to respond and react to each invitation. The cycle not only perpetuates the process with higher and higher user engagement, but it also accelerates it.

Sharpening the competitive edge

Gourville claims that for new entrants to stand a chance they can't just be better, they must be nine times better. Why such a high bar? Because old habits die hard and new products or services need to offer dramatic improvements to shake users out of old routines. Gourvilles writes that products that require a high degree of behavior change are doomed to fail even if the benefits of using the new product are clear and substantial. Ex. Keyboard.

Building the mind monopoly

Altering behavior requires not only an understanding of how to persuade people to act, for example, the first time they land on a web page but also necessitates getting them to repeat behaviors for long periods, ideally for the rest of their lives.

The enemy of forming new habits is past behaviors and research suggests that old habits die hard. Even when we change our routines, neural pathways remain etched in our brains, ready to be reactivated when we lose focus.

Whenever the company can identify the user through tracking technology, it improves search results based on past behaviors to deliver a more accurate and personalized experience, reinforcing the user's connection with the search engine. The more the product is used, the better the algorithm gets, and thus the more it is used.

In the habit zone

A company can begin to determine its product's habit-forming potential by plotting two factors: frequency ( how often the behavior occurs) and perceived utility ( how useful and rewarding the behavior is in the user's mind over alternative solutions.)

A 2010 study found that some habits can be formed in a matter of weeks while others can take more than five months. The researchers also found that the complexity of the behavior and how important the habit was to the person greatly affected how quickly the routine was formed.

Vitamins versus painkillers

"Painkillers solve an obvious need, relieving a specific pain, and often have quantifiable markets." "Vitamins, by contrast, do not necessarily solve an obvious pain point. Instead, they appeal to users' emotional rather than functional needs." "a habit is when not doing an action causes a bit of pain."

Habits are not the same things as addictions. The latter word means persistent, compulsive dependencies on a behavior or substance. Addictions, by definition, are self-destructive. Thus, it is irresponsible to make products that rely on creating and maintaining user addictions because doing so would mean intentionally harming people.

A habit, on the other hand, is a behavior that can have a positive influence on a person's life. Habits can be healthy or unhealthy, and you likely have several helpful habits you carry out throughout your day.

Remember and share

  • 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)
  • Designing habit-forming product 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

Do this now

  • What habits does your business model require?
  • what problem are users turning to your product to solve?
  • How do users currently solve that problem and why does it need a solution?
  • How frequently do you expect users to engage with your products?
  • What user behavior do you want to make into a habit?


Habits are not created, they are built upon

External triggers

"External triggers are embedded with information, which tells the user what to do next"

More choices require the user to evaluate multiple options. Too many choices or irrelevant options can cause hesitation, confusion, or worse, abandonment. Reducing the thinking required to take the next action increases the likelihood of the desired behavior occurring unconsciously.

Types of external triggers

  1. Paid Triggers
    Advertising, search engine marketing, and other paid channels are commonly used to get users' attention and prompt them to act. Paid triggers can be effective but costly ways to keep users coming back.
  2. Earned triggers
    Earned triggers are free in that they cannot be bought directly, but they often require investment in the form of time spent on public and media relations. Favorable press mentions hot viral videos and featured app store placements are all effective ways to gain attention.
  3. Relationship triggers
    One person telling others about a product or service can be a highly effective external trigger for action.
  4. Owned triggers
    Owned triggers consume a piece of real estate in the user's environment. They consistently show up in daily life and it is ultimately up to the user to opt into allowing these triggers to appear.

Internal Triggers

"Internal triggers manifest automatically in your mind. Connecting internal triggers with a product is the brass ring of consumer technology"

"in the case of internal triggers, the information about what to do next is encoded as a learned association in the user's memory"

The association between an internal trigger and your product, however, is not formed overnight. It can take weeks or months of frequent usage for internal triggers to latch onto cues. New habits are sparked by external triggers, but associations with internal triggers are what keep users hooked.

Building for triggers

"The ultimate goal of a habit-forming product is to solve the user's pain by creating an association so that the user identifies the company's product or service as the source of relief."

"When the research focuses on what people actually do ( watch cat videos) rather than what they wish they did ( produce cinema-quality home movies) it actually expands possibilities"

"If you want to build a product that is relevant to folks, you need to put yourself in their shoes and you need to write a story from their side. So, We spend a lot of time writing what's called user narratives"

A clear description of users, their desires, emotions, and the context in which they use the product is paramount to building the right solution. In addition to Dorsey's user narratives, tools like customer development, usability studies, and empathy maps, are examples of methods for learning about potential users.

Naturally, we might have come to another conclusion by starting with a different persona, varying the narrative, or coming up with different hypothetical answers along the chain of whys. Only an accurate understanding of our user's underlying needs can inform the product requirements.

Remember and share

  • 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 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.
  • 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.

Do this now

  • Who is your product's user?
  • What is the user doing right before your intended habit?
  • Come up with three internal triggers that could cue your user to action.
  • Which internal trigger does your user experience most frequently?
  • Finish this brief narrative using the most frequent internal trigger and the habit you are designing: "every time the user (internal trigger), he/she (first action of intended habit).
  • What might be places and times to send an external trigger
  • How can you couple an external trigger as closely as possible to when the user's internal trigger fires?
  • Think of at least 3 conventional ways to trigger your user with current technology ( email, notification, text messages) then stretch yourself to come up with at least three crazy or currently impossible ideas for ways to trigger your user (wearable computers, biometric sensors, carrier, pigeons, etc). You could find that your crazy ideas spur some new approaches that may not be nutty after all. In a few years, new technologies will create all sorts of currently unimaginable triggering opportunities.


The trigger, driven by internal or external cues, informs the user of what to do next; however, if the user does not take action, the trigger is useless. To initiate action, doing must be easier than thinking. Remember, a habit is a behavior done with little or no conscious thought. The more effort, either physical or mental required to perform the desired action, the less likely it is to occur.

Action Versus Inaction

The Director of the Persuasive Technology Lab at Stanford university has developed a model that serves as a relatively simple way to understand what drives our actions.

Dr. B.J. Fogg posits that there are three ingredients required to initiate any and all behaviors: (1) the user must have sufficient motivation (2) the user must have the ability to complete the desired action and (3) a trigger must be present to activate the behavior


While a trigger cues an action, motivation defines the level of desire to take that action.

"Motivation as 'the energy for action'"

Fogg states that all humans are motivated to seek pleasure and avoid pain to seek hope and avoid fear and finally, to seek social acceptance and avoid rejection.

What motivates some people will not motivate others, a fact that provides all the more reason to understand the needs of your particular target audience.

While internal triggers are the frequent everyday itch experienced by users, the right motivators create action by offering the promise of desirable outcomes (ex. satisfying scratch).

Consequently, any technology or product that significantly reduces the steps to complete a task will enjoy high adoption rates among the people it assists.

"Take a human desire, preferably one that has been around for a really long time... identify that desire and use modern technology to take out steps."

The ease or difficulty of doing a particular action affects the likelihood that a behavior will occur. To successfully simplify a product we must remove obstacles that stand in the user's way. According to the Fogg behavior model, the ability is the capacity to do a particular behavior.

Fogg describes 6 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 the focus required to take an action
  • Social deviance - how accepted the behavior is by others.
  • Non-routine - according to Fogg. "How much the action matches or disrupts existing routing.

All three parts of B = MAT must be present for a singular user action to occur, without a clear trigger and sufficient motivation there will be no behavior. However, for companies building technology solutions, the greatest return on investment generally comes from increasing a product's ease of use.

The fact is, increasing motivation is expensive and time-consuming, website visitors tend to ignore the instructional text, they are often multitasking, and have little patience for explanations about why or how they should do something. Influencing behavior by reducing the effort required to perform an action is more effective than increasing someone's desire to do it. Make your product so simple that users already, know how to use it, and you've got a winner.

For example on twitter, driving users to install the app on their phones leads to the highest rates of repeat engagement.

On heuristics and perception

There are many counterintuitive and surprising ways companies can boost users' motivation or increase their ability by understanding heuristics, the mental shortcuts we take to make decisions and form opinions.

The scarcity effect

The appearance of scarcity affected their perception of value.

The framing effect

The mind takes shortcuts informed by our surroundings to make quick and sometimes erroneous judgments.

The framing heuristic not only influences our behaviors; it literally changes how our brain perceives pleasure.

The anchoring effect

People often anchor to one piece and information when making a decision

The endowed progress effect

The study demonstrates the endowed progress effect, a phenomenon that increases motivation as people believe they are nearing goals.

Variable Reward

The study revealed that what draws us to act is not the sensation we receive from the reward itself, but the need to alleviate the craving for that reward.

To Hold our attention, products must have an ongoing degree of novelty. Our brains have evolved over millennia to help us figure out how things work. Once we understand causal relationships, we retain that information in memory. Our habits are simply the brain's ability to quickly retrieve the appropriate behavioral response to a routine or process we have already learned. Habits help us conserve our attention for other things while we go about the tasks we perform with little or no conscious thought.

However, when something breaks the cause-and-effect pattern we've come to expect when we encounter something outside the norm, we suddenly become aware of it again. Novelty sparks our interest and makes us pay attention.

Our brains are adapted to seek rewards that make us feel accepted, attractive, important, and included.

The need to acquire physical objects, such as food and other supplies that aid our survival is part of our brain's operating system.

A reward of the self

There are the variable rewards we seek for a more personal form of gratification.

We even pursue these rewards when we don't outwardly appear to enjoy them. Ex. video games.

Important considerations for designing reward systems

Only by understanding what truly matters to users can a company correctly match the right variable reward to their intended behavior.

Variable rewards are not magic fairy dust that a product designer can sprinkle onto a product to make it instantly more attractive. The reward must fit into the narrative of why the product is used and align with the user's internal triggers and motivations.

Maintain a sense of autonomy

The turn of phrase has not only proven to increase how much bus fare people give but has also been effective in boosting charitable donations and participation in voluntary surveys. In fact, a recent meta-analysis of forty-two studies involving over twenty-two thousand participants concluded that these few words, placed at the end of a request, are a highly effective way to gain compliance, doubling the likelihood of people saying yes. The magic words the researchers discovered? The phrase "But you are free to accept or refuse"

Companies that successfully change behaviors present users with an implicit choice between their old way of doing things and a new, more convenient way to fulfill existing needs.

By maintaining the users' freedom to choose, products can facilitate the adoption of new habits and change behavior for good.

Beware of finite variability

"Finite variability" is an experience that becomes predictable after use.

Experiences with finite variability become less engaging because they eventually become predictable.

Products utilizing infinite variability stand a better chance of holding on to users' attention, while those with finite variability must constantly reinvent themselves just to keep pace.

Which rewards should you offer?

Variable rewards are a powerful inducement to repeat actions. Understanding what moves users to return to habit-forming products gives designers an opportunity to build products that align with their interests. However, simply giving users what they want is not enough to create a habit-forming product.


A psychological phenomenon known as the escalation of commitment has been shown to make our brains do all sorts of funny things. The power of commitment makes some people play video games until they keep over and die. It is used to influence people to give more to charity. It has even been used to coerce prisoners of war into switching allegiances. The commitments we make have a powerful effect on us and play an important role in the things we do, the products we buy, and the habits we form.

"The more users invest time and effort into a product or service, the more they value it. In fact, there is ample evidence to suggest that our labor leads to love."

We irrationally value our efforts.

To avoid the cognitive dissonance of not liking something that others seem to take so much pleasure in, we slowly change our perception of the thing we once did not enjoy. Examples are spy foods, beer, and alcohol.

Together the three tendencies just described influence our future actions: The more effort we put into something, the more likely we are to value it; we are more likely to be consistent with our past behaviors; and finally, we change our preferences to avoid cognitive dissonance.

These tendencies of ours lead to a mental process known as rationalization, in which we change our attitudes and beliefs to adapt psychologically. Rationalization helps us give reasons for our behaviors, even when those reasons might have been designed by others.

The cognitive changes that lead to behavior change help power the shift in how we view the products and services we use.

The big idea behind the investment phase is to leverage the user's understanding that the service will get better with use ( and personal investment). Like a good friendship, the more effort people put in, the more both parties benefit.

Storing value

"The stored value users put into the product increases the likelihood they will use it again in the future and comes in a variety of forms."

"The collections of memories and experiences, in aggregate, become more valuable over time and the service becomes harder to leave as users' personal investment in the site grows.

"The company found that the more information users invested in the site, the more committed they become to it"

"Once users have invested the effort to acquire a skill, they are less likely to switch to a competing product."

Ultimately, habit-forming products create a mental association with an internal trigger. Yet to create the habit, users must first use the product through multiple cycles of the hook model.

"Habit-forming technologies leverage the user's past behavior to initiate an external trigger in the future."

The habit-forming technology increases the value of the product with each pass through the Hook. Through successive cycles of the Hook Model, users increase their affinity for the experience. They increasingly come to rely on the product as the solution to their problems until finally the new habit and routine is formed.

The more users invest in a product through tiny bits of work, the more valuable the product becomes in their lives and the less they question its use. Users do not stay hooked forever, though. Invariably, the next big thing will come along and provide a better, more compelling hook. However, by creating habits fueled by investments in a product or service, companies make switching to a competitor difficult. User habits are hard to break and confer powerful competitive advantages to any company fortunate enough to successfully create them.

What are you going to do with this?

You are now equipped to use the Hook Model to ask yourself these five fundamental questions for building effective hooks:

  1. What do users really want? What pain is your product relieving? (internal trigger)
  2. What brings users to your service? (external trigger)
  3. What is the simplest action users take in anticipation of reward, and how can you simplify your product to make this action easier? (Action)
  4. Are users fulfilled by the reward yet left wanting more? (Variable reward)
  5. 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)

"Manipulation is an experience crafted to change behavior"

  1. The facilitator - In building a habit for a user other than you, you cannot consider yourself a facilitator unless you have experienced the problem firsthand. The role of facilitator fulfills the moral obligation for entrepreneurs to build a product they will themselves use and that they believe materially improves the lives of others. As long as the procedures are in place to assist those who form unhealthy addictions, the designer act with a clean conscience.
  2. The Peddler - Peddlers tend to lack the empathy and insights needed to create something users truly want.
  3. The entertainer - Entertainment is a hits-driven business because the brain reacts to a stimulus by wanting more and more of it, ever hungry for continuous novelty.
    "Building an enterprise on ephemeral desires is akin to running on an incessantly rolling treadmill: You have to keep up with the constantly changing demands of your users."
  4. The dealer - creating a product that the designer does not believe improves users' lives and that he himself would not use is called exploitation.

Case Study: The bible app

The most highly regarded entrepreneurs are driven by meaning, a vision for the greater good that drives them forward.

The hook model is a framework based on human psychology and a close examination of today's most successful habit-forming products.

According to the company's publicist, "community emails can serve as a nudge to open the app."

The app uses the principle that by making an intended action easier to do, people will do it more often.

Habit testing and where to look for habit-forming opportunities.

The hook model can be a helpful tool for filtering out bad ideas with low habit potential as well as a framework for identifying room for improvement in existing products.

Building a habit-forming product is an iterative process and requires user-behavior analysis and continuous experimentation.

Habit testing. It is a process inspired by the "build, measure, learn" methodology championed by the lean start-up movement. Habit testing offers insights and actionable data to inform the design of habit-forming products. It helps clarify who your devotees are, what parts (if any) of your product are habit-forming, and why those aspects of your product are changing user behavior.

Step 1 : identity

First, define what it means to be a devoted user. How often "should" one use your product?

You are looking for a realistic guess to calibrate how often typical users will interact with your product.

Once you know how often users should use your product, dig into the numbers to identify how many and which type of users meet this threshold. As a best practice, use cohort analysis to measure changes in user behavior through future product iterations.

Step 2: Codify

Every product has a different set of actions that devoted users take; the goal of finding a habit path is to determine which of these steps is critical for creating devoted users so that you can modify the experience to encourage this behavior.

Step 3: Modify

Habit testing is a continual process you can implement with every new feature and product iteration.

Tracking users by cohort and comparing their activity with that of habitual users should guide how products evolve and improve.

Discovering habit-forming opportunities

"Instead of asking ' what problem should I solve?' ask ' what problem do I wish someone else would solve for me?"

Studying your own needs can lead to remarkable discoveries and new ideas because the designer always has a direct line to at least one user; him or herself.

Careful introspection can uncover opportunities for building habit-forming products.

"As you go about your day, ask yourself why you do or do not do certain things and how those tasks could be made easier or more rewarding."

Observing your own behavior can inspire the next habit-forming product or inform a breakthrough improvement to an existing solution.

Nascent behaviors

Many habit-forming technologies begin as vitamins, nice-to-have products that, over time become must-have painkillers by relieving an itch or pain.

Enabling technologies

"Wherever new technologies suddenly make a behavior easier, new possibilities are born."

Interface changes.

Whenever a massive change occurs in the way people interact with technology, expect to find plenty of opportunities ripe for harvesting. Changes in interface suddenly make all sorts of behaviors easier. Subsequently, when the effort required to accomplish an action decreases, usage tends to explode.

By looking forward to anticipating where interfaces will change, the enterprising designer can uncover new ways to form user habits.

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