Forming user habits is an important aspect in ensuring the success of a new company.

  • Why do some products capture widespread attention, while others flop?
  • What makes us engage with certain products out of sheer habit?
  • Is there a pattern underlying how technologies hook us?

This book refers to products in the context of businesses that require ongoing, unprompted user engagement, and therefore need to build user habits.

This book does not cover business models for delivering customer value, or methods for profitable customer acquisition.

These are my personal notes, which I hope others will find useful.

These notes are not intended to be a substitute for the book. You can buy the book here: Hooked: How to Build Habit-Forming Products -

Author’s blog:


Habits are behaviors done with little or no conscious thought.

Habits are not created, they are built upon.

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

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

For a new action to become a habit, the user must perceive a high degree of utility, either by gaining pleasure, or avoiding pain.

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.

Some behaviors never become habits because they are not frequent enough.

Behaviors that occur with enough frequency and utility enter the habit zone:

The Habit Zone

Habits cannot form outside of the habit zone.

Habit forming products

Companies that build habit forming products link their products to internal triggers, so that users are motivated to come back without any external prompting.

Habit forming companies link their services to users daily routines and emotions.

Habit forming products often start as nice-to-haves, but once the habit is formed, they become must-haves.

Habit forming products alleviate the users pain.

Habit forming products are not necessarily produced to encourage negative behaviors. When harnessed correctly, technology can enhance our lives through behaviors that improve our relationships, make us smarter, and increase productivity.

One aim of a habit forming product is to influence customers to use the product on their own, without relying on overt calls to action such as emails, ads, or promotions. Once a habit is formed, the user is automatically triggered to use the product during routine events such as wanting to kill time while waiting in line.

First to mind wins. i.e. a person wants to answer a question, or find out more about a topic, and instinctively search Google, since Google is the first to come to mind when thinking about searching online.

Habit forming products can have several business benefits including:

  • Higher customer lifetime value
  • Greater pricing flexibility
  • Supercharged growth
  • A sharper competitive edge

If you are building a habit forming product, answer these questions:

  • What habits does your business model required?
  • What problem are your 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 product?
  • What user behavior do you want to make into a habit?


Users increase their dependency on a habit forming product by storing value in it. i.e. every email sent and received by Gmail is stored indefinitely, providing users with a lasting repository of past conversations, making it harder to switch because the user would either need to migrate their data, or leave all that historical, valuable data behind.

A better product is not enough

For example, the QWERTY keyboard was designed back in the 1870s to space characters in a way that prevented early (mechanical) typewriters from getting jammed.

The Dvorak keyboard was patented in 1932, and has a much more efficient layout for typists.

Because of the high cost of changing from the QWERTY to Dvorak keyboard (re-learning how to type), and the ubiquity of keyboards with the QWERTY layout, the Dvorak keyboard remains unpopular.

“Many inventions fail because consumers irrationally overvalue the old, while companies irrationally overvalue the new.” - John Gourville

A better product must be at least 9x better than competitors.

User engagement

In 2011, Evernote’s CEO Phil Libin published a chart, with the percentage of sign-ups represented on the y-axis, and time spent on the service on the x-axis. The chart showed that, although usage plummeted at first, it rocketed upward as people formed a habit of using the service. This chart is known as a “smile graph” because of the down-and-up curve, which gives the chart a smile shape.

Evernote Smile Graph

Libin noted that after the first month, only 0.5% of users paid for the service, however this rate gradually increased:

  • By month 33, 11% of users had started paying
  • By month 42, 25% of customers were paying

Frequent usage creates more opportunities to encourage people to invite their friends, broadcast content, and share through word of mouth. Users become brand evangelists, bringing in new users at little or no cost.

Products with higher engagement have the potential to grow faster than rivals. i.e. Google leapfrogging it’s well-established competitors (Altavista, etc), even though it was late to the game.

Viral cycle time is the time it takes a user to invite another user

Habits tend to be LIFO (Last in, first out)

Habits that have been most recently acquired are also the soonest to be abandoned.

The enemy of forming new habits is past behaviors.

Old habits die hard.

It’s possible to manufacture habits by guiding users through a series of hooks.

The Hook Model

The hook model describes an experience designed to connect the users problem to a solution frequently enough to form a habit.

The hook model has four phases: trigger, action, variable reward, and investment.

The Hook Model

Trigger - The first step in the Hook model

Triggers cue the user to take action

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. i.e.

  • Seeing an advertisment
  • Reading a review
  • Getting an email
  • A website link
  • Seeing the app icon on your phone
  • A recommendation from a friend

Internal triggers tell the user what to do next through associations stored in the user’s memory i.e.

  • Feeling a tad bored, and reactively open twitter
  • Feeling a tad lonely, and reactively open Facebook
  • Wanting to answer a question, and reactively search using Google.
  • Wanting to share a photo with friends, and reactively using Instagram.

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

For internal triggers, the information about what to do next is encoded as a learned association in the users memory. The response is often automatic.

Negative emotions (i.e. fear of missing out) frequently serve as internal triggers.

Focusing on what people actually do (i.e. watching cat videos), rather than what people wish they did (i.e. producing cinema-quality home movies), exposes opportunities i.e.

  • Why do people really send text messages?
  • Why do people take photos?
  • What role does watching TV or sports play in their lives?

Ask yourself what pain these habits solve, and what the user might be feeling right before one of those actions.

If you want to build a product that’s relevant to people, you’ve got to put yourself in their shoes. i.e.

  • User narratives
  • Customer development
  • Usability studies
  • Empathy maps
  • Asking “Why” as many times as it takes to get to an emotion based trigger.

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.

Building for Triggers

More choices require the user to evaluate more options, which can lead to confusion, hesitation, or abandonment. Reducing the thinking required to take the next action increases the likelihood of the desired behavior occurring unconsciously.

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.

Things to do next

Answer the following questions:

  • What habits does your business model required?
  • What problem are your 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 product?
  • What user behavior do you want to make into a habit?

Action - The second step of the Hook model

Following the trigger comes the action - the behavior in anticipation of feedback (or a reward)

i.e. to answer a question, reactively searching Google

If the user does not take action, the trigger is useless.

The more effort (either physical or mental) required to take an action, the less likely it is to occur.

Companies leverage two basic pulleys of human behavior to increase the likelihood of an action occurring:

  • The ease of performing the action
  • The psychological motivation of doing it

The Fogg Behavior Model

Fogg Behavior Model

There is a model by BJ Fogg which 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
  3. A trigger must be present to activate the behavior.

All of the above must be present to at the same time, to sufficient degrees, in order to initiate a given behavior.

To increase the likelihood of a desired behavior, ensure a clear trigger is present. Nexxt, 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:

  1. Seeking pleasure and avoiding pain
  2. Seeking hope and avoiding fear
  3. Seeking social acceptance while avoiding social rejection

Ability dependant on users and their context in the moment.

Ability is influenced by six factors of:

  1. Time
  2. Money
  3. Physical effort
  4. Brain cycles
  5. Social deviance
  6. Non-routineness

Elements of simplicity

Fogg describes six “elements of simplicity” which influence a task’s difficulty.

  • Time - how long it takes to complete a task’s 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 existing routines.

Some examples:

  • Logging in with Google / Facebook - sites that offer this, make it easier to sign up as they don’t require the user to create a new account, or remember a new password.
  • “Share with twitter” button - makes it easy to share an interesting article on twitter, allowing a one-click way to set up a tweet directly from a page, reducing the cognitive effort by creating a pre-set message.
  • Making the camera app directly launchable from the home screen (Apple phones, newer Android phones), reducing friction taking photos, by skipping the need to unlock the phone.
  • Infinite scroll on pinterest; the user doesn’t need to take an action, or make a decision to navigate to the next page, they can just keep scrolling.

Heuristics and cognitive biases

Heuristics are cognitive shortcuts we take to make quick decisions.

Most people are unaware of how heuristics and cognitive biases influence their decisions.

Stephen Anderson, author of Seductive Interaction design, created a tool called Mental Notes. It consists of a deck of 50 cards, where a cognitive bias is written on each card, and is intended to spark product team conversations around how a product team might use these biases to increase the likelihood of a desired behavior.

Here are four examples of cognitive biases:


The perception of scarcity can increase the perceived value of something.


Framing can also increase the perceived value. For example, when Joshua Bell played violin a subway station. This person regularly sells out in venues such as the Kennedy Center, and Carnegie hall, for hundreds of dollars per ticket. In the subway, there was little interest.


Anchoring can increase perceived value, since people often anchor to one piece of information when making a decision.

Endowed progress

Endowed progress increases the chance of a person taking an action.

Motivation increases as people believe they are nearing a goal. i.e. two groups of customers were given punch chards, awarding a free car wash when the card was fully punched. For one group, they were given cards with 10 slots, with 2 pre-punched. The second group were given cards with 8 slots, and none punched. Despite there being the exact same number of unpunched slots on the cards, the first group had an 82% higher completion rate.

Linkedin and Facebook use endowed progress to encourage people to divulge more information about themselves when completing their online progress. i.e. Linkedin’s “Improve your profile strength” prompt.

Things to do next

Answer the following questions:

  • Who is your product’s user?
  • What is the user doing right before your intended habit?
  • What are 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 (insert trigger), he/she (first action of intended habit)”, then:

  • What is the user is doing right before the first action of the above 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?
  • What are three conventional ways to trigger your user with current technology? (i.e. emails, notifications, text-messages, etc).
  • What are three unconventional ways to trigger your user with uncommon, or non-current technology? (i.e. biometric sensors, wearable computers, etc)

Based on your answers above:

Walk through the path your users would take to user your product or service, beginning from the time they feel their internal trigger, to the point where they receive their expected outcome.

Variable Reward - The third step of the Hook Model

The variable reward phase is where the user is rewarded for solving a problem, reinforcing their motivation for the action taken in the action phase.

The unsurprising result of the fridge light coming on when you open the door isn’t going to make you want to keep opening the door over and over.

If the fridge contained a random treat every time you opened the door, intrigue is created.

Levels of dopamine surge when the brain is expecting a reward.

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.

Variable rewards are powerful tools that companies implement to hook users.

Introducing variability multiplies the dopamine reward effect, creating a focused state which suppresses the areas of the brain associated with judgement and reason, while activating the parts associated with wanting and desire.

There are three variable reward types.

Variable Reward Types

The Tribe

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

i.e. getting feedback from your social group in the form of “likes” on Facebook, Instagram, Twitter

The Hunt

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

i.e. Twitter and Pinterest which are filled with a mix of mundane and relevant content, which create an enticing and unpredictable experience; on occasion, the user might find a particularly interesting piece of content, other times they won’t - a form of variable reward.

Rewards of the self

Fueled by intrinsic motivation. People desire, among other things, to gain a sense of competency. Adding an element of progression, completion, and mystery to the goal makes the pursuit all the more enticing.


  • Video games, where characters are advanced through levels, where each level unlocks new abilities
  • The app ‘Mailbox’ which was acquired by Dropbox in 2013. This app divided emails in sorted folders which increased the frequency of ‘inbox zero’, giving the users the sense that they are processing their inbox more efficiently.

Important considerations for designing reward systems

Most habit forming products and services utilise one or more of the three variable reward types: the tribe, the hunt, or the self.

Email utilises all three of the variable reward types:

We are subconsciously compelled to check email because:

  • We have a social obligation to respond to email and the desire to be seen as agreeable (rewards of the tribe)
  • We may be curious about what information is in our inbox. Perhaps something related to our career, or business awaits us. Checking email informs us of opportunities or threat to our material possessions or livelihood. (rewards of the hunt)
  • Email is a task, categorise and act to eliminate unread messages, feeling compelled to gain control of our inbox. (rewards of the self)

Variable rewards are not a free pass

Mahalo was released in May 2007, and offered monetary rewards initially, with it’s user base peaking at 14.1 million. Eventually, users began to lose interest. Even though the bounties were variable, monetary rewards were not enticing enough. Mahalo had an incomplete understanding of it’s user’s drivers; ultimately people didn’t want to use a Q&A site to make money, and users were better off spending their time earning an hourly wage, and the rewards were too small to matter.

In 2010, Quora was released, and didn’t offer any monetary reward. Instead, Quora demonstrated that social rewards, and the variable reinforcement of recognition for peers proved to be much more frequent and salient motivators.

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

Maintain a sense of autonomy

People have an instinctive rejection to being told what to do. Reaffirming the person’s freedom to choose disarms their instinctive rejection of being told what to do.

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.

Beware of finite variability

Experiences with finite variability become increasingly predictable with use, and lose their appeal over time.

Experiences with infinite variability, remain unpredictable, and are more likely to maintain interest.


Games played to completion have finite variability.

Games such as World of Warcraft, which is frequently played with teams, and has frequent expansions, are much closer to infinite variability.

Things to do next

Answer the following questions:

  • How many steps does it take before users obtain the reward they came for?
  • How does this process compare with competing products and services?
  • Which aspects described in the Fogg Behavior Model are limiting your users ability to accomplish tasks that will become habits?
  • What are three testable ways to make intended tasks easier to complete?
  • How might you apply heuristics to make habit-forming actions more likely?

Speak with five of your customers in an open ended interview to identify what they find enjoyable or encouraging about using your product:

  • Are there any moments of delight or surprise?
  • Is there anything they find particularly satisfying about using the product?

Review the steps your customer takes to use your product, or service habitually. What outcome (reward) alleviates the user’s pain? Is the reward fulfilling, yet leave the user wanting more?

Brainstorm three ways your product might heighten users’ search for variable rewards using:

  1. Rewards of the tribe - gratification from others.
  2. Rewards of the hunt - material goods, money, or information.
  3. Rewards of the self - mastery, completion, competency, or consistency.

Investment - The fourth stage of the Hook model

Simply giving users what they want is not enough to create a habit forming product. The feedback from the first three steps (trigger, action, variable reward) still misses the final critical phase, which is the investment phase.

The investment phase is the fourth step in the Hook Model; when the user invests into the product, improving the service as a result i.e.

  • Spending time using the product
  • Adding data to the product (i.e. Tweets, Facebook Posts, Pinterest boards)
  • Inviting friends to use the product (social capital)
  • Stating preferences / customising the product to suit their interests

Investments increase the likelihood of users returning by improving the service the more it’s used. They enable the accrual of stored value in the form of content, data, followers, reputation, or skill.

User habits are hard to break, and give a powerful competitive advantage to companies that create them.

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 stage, when users are primed to reciprocate.

Investments increase the likelihood of users passing through the Hook again by loading the next trigger to restart the cycle.


Linkedin found that the more information users added to the site, the more committed they became to it.

Josh Elman, early senior product manager at linkedin said “If we could get users to enter just a little information, they are more likely to return.”


On Twitter, for the user seeking followers, the more followers a user has, the more likely they are to return to the service.

One way to gain followers on Twitter is to tweet interesting content. This means that to acquire more followers, the user must invest in producing more, and better tweets. This process increases the value for both sides. No one wants to rebuild a loyal following they had worked hard to acquire and nurture.


Learning to use a product is also a form of invested value. Once a user has acquired a skill, using the service becomes easier, and moves them to the right in the ability axis of the Fogg usability model.

For example, learning to use Adobe Photoshop is difficult at first, but as the user becomes more familiar with using the product, through hours of practice, tutorials, etc, they acquire a sense of mastery (reward of the self).

Once a user has put in effort to acquire a skill, they are less likely to switch to a competing product.

Things to do next

  • Review your flow, what investment are your users doing to increase their likelihood of returning?
  • Brainstorm three ways to add small investments to your product to:
    • Load the next trigger
    • Store value as data i.e. content, followers, reputation, skill.
  • Identify how long it takes for a trigger to re-engage your users. How can you reduce the delay to shorten time spent cycling through the Hook?

Loading the next trigger - Repeating the Hook cycle

Habit forming technologies leverage the users’ past behavior to initiate an external trigger in the future. (Task management app)

Designed to get users to invest early on

Trigger: During first use, teaches users how to use the product. The app’s easy to follow instructions are the trigger.

Action: Doing what the instructions tell the user to do.

Variable Reward: Congratulatory message for completing actions

Investment: New users are instructed to connect the app to their calendar service, which gives access to their schedule.

Repeating the hook cycle:

As part of giving access to the user’s calendar, they also give the app permission to send a notification after the next scheduled meeting ends. This eternal trigger prompts the user to return to the app to record a follow-up task from the meeting they just attended, which aligns with the moment the user is most likely to feel the internal trigger of anxiety of forgetting to do a follow-up task after a meeting. The app has anticipated a need, and sets users up for success.

Case Study: The Bible App

  • The bible app was far less engaging as a desktop website; the mobile interface increased accessability and usage by providing frequent triggers.
  • The bible app increaseds users’ ability to take action by front-loading interesting content and providing an alternative audio version.
  • By separating verses into small chunks, users find the bible easier to read on a daily basis, not knowing what th next verse will be (variable reward)
  • Every annotation, bookmark, and highlight stores data (and value) in the app, further committing users.

Habit Testing

Simply coming up with ideas is not enough to develop a habit forming product.

The process of creating habit forming products requires patience and persistence.

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

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

The Habit Testing process is inspired by the “build, measure, learn” process.

Habit Testing requires an existing product to test.

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

Habit Testing

Identify - step 1

Define what it means to be a devoted user. How often “should” one use your product. i.e Instagram is often used daily, whereas movie review sites are often used weekly, or even less frequently - whenever somebody is thinking about seeing a film.

Look at any publicly available data on similar products to help define your users and engagement targets.

Look for a realistic guess to odentify what proportion and what type of users meet the criteria of habitual user. The author’s rule thumb is about 5% of users.

If less than 5% of users find your product valuable enough to use it as much as you predicted, you may have a problem - either you identified the wrong group of people, or your product needs to go back to the drawing board.

If you exceeded 5%, then it’s time to codify the steps they took using your product, to understand what hooked them.

Codify - step 2

Look for a Habit Path - a series of similar actions shared by your most loyal users. i.e. in Twitter’s early days, they found that once a user followed 30 other members, they hit a tipping point that dramatically increased the odds that they would keep using the site.

The goal of finding the Habit Path is to determine which steps are critial for creating deoted users, so that you can modify the experience to encourage this behavior.

Modify - step 3

Now that you’ve found a Habit Path, it’s time to modify your product in a way that encourages new users to go down the same path. i.e.

  • Updating the registration funnel
  • Content changes
  • Feature removal
  • Increased emphasis on an existing feature

Use cohort analysis to measure changes in user behavior through future product iterations.

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

Many companies have found success in driving new habit formation by identifying how changing user interactions can create new routines.

Things to do next

Take a minute to see where you fall on the Manipulation Matrix:

The Manipulation Matrix

Then answer the following questions:

  • Do you use your own product or service?
  • How does it influence positive or negative behaviors?
  • How does it make you feel?
  • Are you proud of the way you are influencing the behavior of others?

Discovering habit-forming opportunities

Habit Testing requires an existing product to test, but what if you don’t have a product yet?

Y Combinator’s Paul Graham advises entrepreneurs to leave sexy sounding business ideas behind, and build for their own needs.

Instead of asking “which problem should I solve?”, ask “what problem do I wish somebody would solve for me?”

Studying our own needs can lead to remarkable discoveries and new ideas because the designer always has a direct line to at least one user themselves.

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

Nascent behaviors

Sometimes technologies that appear to cater only to a small niche, will cross into the mainstream, but only if they cater to a broad need.

The invention of the telephone was initially dismissed by William Preece, the chief engineer of the british post office: “The Americans have need of the telephone, but we do not; we have plenty of messenger boys”

In 1911, Ferdinand Foch, a future commander in chief during World war 1 said “Airplanes are interesting toys, but are of no military value”

More recently, in 1995, Clifford Stoll wrote a newsweek article “The truth is that no online database will replace your daily newspaper”, and that the idea of buying books over the internet will never become mainstream.

Enabling technologies

Whenever new technologies make a behavior easier, new possibilities are born.

Identifying areas where a new technology makes cycling through the Hook Moder faster, more frequent, or more rewarding, provides fertile ground for developing new habit forming products.

Interface change

Whenever a massive change occurs in the way people interact with technology, expect to find plenty of opportunities ripe for harvesting

Changes in interface make all sorts of behaviors easier.

When the effort to accomplish an action decreases, usage tends to explode.

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

Things to do next

  • Perform habit testing to identify the steps users take toward long-term engagement
  • Be aware of your behaviors and emotions as you use everyday products, and ask yourself:
    • What triggered me to use these products?
    • Was I prompted externally or through internal means?
    • Am I using these products as intended?
    • How might these products improve onboarding funnels, re-engage users through additional external triggers, or encourage users to invest in their services?
  • Speak with three people outside your social circle to discover which apps occupy the first screen on their mobile devices. Ask them to use these apps as they normally would, and see if you uncover any unnecessary or nascent behaviors.
  • Brainstorm five new interfaces that could introduce opportunities or threats to your business.

More Info

Startup Grind Global 2017 - How to Build Habit-Forming Products

Buy the book here: Hooked: How to Build Habit-Forming Products -

The Power of Habit: Why We Do What We Do in Life and Business

How Technology Hijacks People’s Minds

Thanks for reading!

I hope you found this post useful. Do you have any questions? Are there any follow-up blog posts you’d like me to write relating to this? Feel free to leave any feedback in the comments below.