Hooked: How to Build Habit-Forming Products by Nir Eyal [Book Summary]

Introduction: The Hook Model

The importance of habits in business

  • For many companies, turning their products into habits — behaviors requiring no conscious thought — drives a lot of value. This makes loyalty as important as gaining millions of customers.
  • Once a product has become a habit, it does not require extensive advertising to ensure usage; it is linked to users’ emotions and routines.
  • The result is that users begin considering these products indispensable, which ensures repeated use and, in turn, continued success for the companies that manage to create such products.
  • But how do successful companies actually go about creating habit-forming products? Is this all chance, or is there a technique to it? This book covers some of the key aspects that any designer or seller of a habit-forming product would do well to keep in mind.

What are hooks?

  • Hooks are a series of experiences that can together modify user behavior and encourage formation of new habits.
  • As we will see, greater accessibility, more data and improved speed of delivery have increased the likelihood of hooks being employed to drive habit formation in our times.
  • The hooks employed by companies essentially follow a four-phase process called the Hook Model. Successful products go through multiple cycles of these four phases to reach a refined stage where users keep coming back for more on their own, without any need for aggressive marketing by the company.
  • The four phases of the Hook Model are:
  1. Trigger — External or internal cues that prompt certain behavior
  2. Action — Use of the product, based on ease of use and motivation
  3. Variable Reward — The reason for product use, which keeps the user engaged
  4. Investment — A useful input from the user that commits him to go through the cycle again

Chapter 1: The Habit Zone

Benefits of habit-forming

  • Getting consumers to form habits related to their products can be critical for many companies to succeed, but it is not necessary for every single company.
  • For cases where it is needed, and where a company successfully manages to achieve it, habit forming can have a number of benefits. These include:
  • increased customer lifetime value (CLTV) — the amount of money that the company can make from customers before they move to competing offerings
  • more flexibility in raising prices or charging for premium services
  • supercharged growth by word-of-mouth publicity (characterized by Viral Cycle Time — the amount of time taken by a user to invite another user)
  • greater competitive edge, because the competition finds it difficult to make inroads, e.g. people continue to use the QWERTY keyboard despite better keyboards available
  • But people are creatures of habits, and creating new ones requires them to forget certain old ones.
  • This means that for new types of behavior to really become ingrained into our decision-making systems, they need to be reinforced again and again.
  • The benefit is that once you have succeeded in turning your product into a habit, another competing product will find it tougher to displace your product, e.g. Google’s ubiquity and synonymity with Internet search has meant that products that are not particularly bad, like Bing, have failed to become as popular.

How to test the habit-forming potential of your product?

  • Use the frequency-vs.-perceived utility plot. If the product falls in the Habit Zone, i.e. is used often and has a high enough utility compared to competing solutions, then using it can become default behavior for a consumer.
  • In one of the two examples marked in the figure, a single search result on any engine other than Google is not noticeably poorer than what you would get on Google, but Google is used so frequently that it is the option most of us turn to.
  • On the other hand, purchasing on Amazon is nowhere as frequent as much of our other online activity, but its perceived utility is higher because we know that every time we log on to Amazon, the likelihood of finding the product we are looking for is high and it is also going to be available at a competitive price.
  • The position of a product on this chart is not static — many habit-forming products start off as vitamins, but with repeated use, turn into painkillers that satisfy the itch to use them.
  • Vitamins are products that do not solve an obvious problem, but feel nice to have, while painkillers are products that cater to a very obvious need.
  • Many products that are habits for us now because of their perceived utility to us might have been less important to begin with.
  • Before we delve further into the Hook Model, an important caveat: In the quest to encourage consumers to form habits, product designers and sellers should not forget that this is a type of manipulation. Conscientious sellers always need to ensure that the habits, or addictions, they encourage are healthy. We will consider this very important aspect a few chapters later.

Chapter 2: Trigger (Phase 1)

  • Habits, much like pearls, need a foundation and layer upon layer (of continued behavior change) to be completely formed. Triggers are the cue or the foundation for this behavior change.
  • Triggers can be of two types: external and internal.

External triggers

  • These are bits of information from users’ surroundings that prompt them to perform an action. Types include:
  • Paid triggers — channels like advertising that capture attention, but are too expensive for the long run
  • Earned triggers — continued media presence, like viral video and press mentions, which can be difficult to sustain for any product
  • Relationship triggers — come from engaged users who enthusiastically share information with other potential users
  • Owned triggers — most useful, as these employ tacit permission from users to send triggers like app updates and periodic notifications into their personal space

Internal triggers

  • For a product to truly become a habit, its triggers need to move from the external forms to the internal.
  • Internal triggers are driven by users’ emotions and associations stored in their memory.
  • Trying to rid oneself of negative emotions like boredom and loneliness are powerful triggers for using a particular product.
  • As a product relieves these negative emotions repeatedly, our mind subconsciously begins to associate it with this relief.
  • This gradually strengthens the bond with a product, resulting in the formation of a habit, e.g. our reliance on Facebook or Twitter for instant social connection.
  • Designing a habit-forming product requires an understanding of the emotions that are tied to these internal triggers, as well as knowledge of how external triggers can be used effectively to urge a user to perform a certain action.

Chapter 3: Action (Phase 2)

  • The Behavior Model developed by Dr. B.J. Fogg of Stanford University says that the user’s behavior (or action) depends on three prerequisites (B = MAT):
  • M — sufficient motivation
  • A — ability to perform a certain action
  • T — a trigger to prompt the action
  • Therefore, for a clear trigger to be effective, the user should be motivated enough and should be able to perform the action with minimal effect.

What motivates people?

  • There are three Core Motivators that drive behavior in most humans:
  • Desire for pleasure and/or avoidance of pain, e.g. use of scantily clad models in print and TV ads acts as a motivator based on pleasure for certain demographics like teenage boys
  • Desire for hope and/or avoidance of fear, e.g. Barack Obama’s 2008 presidential campaign used the plank of hope to great success
  • Desire for social acceptance and/or avoidance of rejection, e.g. showing friends shown cheering for a sports team in a Budweiser ad makes people identify the product with getting together with friends to watch a game
  • One or more of these core motivators provide the motivation to a user to perform an action.

What factors moderate the ability of people?

  • Even when there is a successful trigger and a compelling enough motivation, a person needs to be able to perform an action. The easier it is to perform it, the greater is the likelihood of it becoming a habit, e.g. the boom in blogging in the 2000s after Blogger made it possible to open a blogging account within minutes or the ease of taking photos with an iPhone.
  • There are six elements of simplicity that have an effect on the ease-of-use of a product:
  • The time it takes to use it
  • The money it costs
  • The degree of physical effort involved
  • The level of mental labor needed
  • The product’s social acceptability
  • The degree to which it matches or disrupts current routines
  • The lower the time, money, physical effort or mental labor involved, or the more socially acceptable it is, or the least deviation it requires from a user’s existing routine, the easier it is for him to perform an action.
  • Consequently, the greater is the likelihood of the product becoming a habit.

How to increase motivation and ability?

  • Between motivation and ability, it is easier to target the latter. Design your products such that it reduces the effort involved for the user, instead of trying to build motivation levels.
  • Both motivation and ability can also be increased using counter-intuitive methods called heuristics. These are mental shortcuts that all of us employ to make quick decisions. Examples include:
  • The scarcity effect — the scarcer a product is, the higher is its perceived value, e.g. the ‘limited stock’ tag on Amazon products ends up increasing sales for those products
  • The framing effect — context can alter the desirability of a product, e.g. the same wine is reported to be tastier if the price is increased
  • The anchoring effect — one aspect of a product is given undue importance over other features, e.g. people end up buying more products of a brand that has a discount sticker on it, even if its quality and the effective cost might be no different than other competing products in the vicinity
  • The endowed progress effect — in case of reward programs, the closer users feel they are to the goal the more motivated they become, e.g. the ‘Improve Your Profile Strength’ step in LinkedIn has a completion bar that starts off all users with part of the bar already filled, strengthening their belief that a full profile is not far away.

Chapter 4: Reward (Phase 3)

  • Variable rewards, and not just any rewards, make users come back to a product again and again by reinforcing the motivation.
  • Finite variability can become boring after a while, while infinite variability sustains user interest.
  • Thus, variable rewards should not only satisfy one or more user needs, but also keep them interested in engaging again (and again) with the product.
  • There are three types of variable rewards:
  • Rewards of the tribe — those that satisfy our social needs by making us feel more important and accepted, e.g. Likes, shares and comments on Facebook
  • Rewards of the hunt — those that satisfy our basic survival instincts by helping us acquire things we consider important, like cash and information, e.g. the mix of mundane and relevant content on Twitter entices users to keep looking for more
  • Rewards of the self — those that help us in self-determination by providing a sense of accomplishment, e.g. apps like Mailbox that segment emails into neat folders, helping achieve a state of ‘inbox zero’, giving a sense of completion and mastery
  • But gamification, or the introduction of rewards, cannot be used blindly to drive user engagement. It is extremely important for product designers to figure out the kind of reward that will motivate their intended users, e.g. Mahalo, a Q&A forum gave monetary rewards to answerers, but bombed, while Quora, a similar service, only provides upvotes, and is very successful.

Chapters 4 to 8



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Payman Taei

Payman Taei


I’m helping the world communicate Visually. #VisualContent Master, Designer, #Entrepreneur, #startups. Founder: Visme & HindSite Interactive