Book Reviews

Hooked: How To Build Habit-Forming Products by Nir Eyal -Book Notes, Summary, and Review

23. Hooked: How To Build Habit-Forming Products -  Nir Eyal

Get it on Amazon

Rating: 6/10

Date of reading: 1st – 4th of July, 2018

Description: How does a habit loop looks like (trigger, action, variable reward, investment) and how you can use it in life, business, products, and services. This book falls into the Habit Trifecta (Charles Duhhig The Power of Habit, B.J. Fogg Tiny Habits).


My notes:




“1. Trigger” ( :10)

“external and internal.” ( :10)

“Following the trigger comes the action: the behavior done in anticipation of a reward.” ( :10)

“the ease of performing an action and the psychological motivation to do it.” ( :10)

“Feedback loops are all around us, but predictable ones don’t create desire. The unsurprising response of your fridge light turning on when you open the door doesn’t drive you to keep opening it again and again. However, add some variability to the mix—suppose a different treat magically appears in your fridge every time you open it—and voilà, intrigue is created.” ( :10)

“The last phase of the Hook Model is where the user does a bit of work. The investment phase increases the odds that the user will make another pass through the Hook cycle in the future. The investment occurs when the user puts something into the product of service such as time, data, effort, social capital, or money.” ( :11)

“”If it can’t be used for evil, it’s not a superpower.” He’s right. And under this definition, building habit-forming products is indeed a superpower.” ( :11)

“”used to help nudge people to make better choices (as judged by themselves).” ( :12)


1: The Habit Zone


“Habit-forming products change user behavior and create unprompted user engagement. The aim is to influence customers to use your product on their own, again and again, without relying on overt calls to action such as ads or promotions.” ( :15)

“customer lifetime value (CLTV): the amount of money made from a customer before that person switches to a competitor, stops using the product, or dies.” ( :16)

“The duo have pointed to consumer psychology as 5 the rationale behind their famed investments in companies like See’s Candies and Coca-Cola. Buffett and Munger understand that habits give companies greater flexibility to increase prices.” ( :16)

“In addition, as usage increased over time, so did customers’ willingness to pay. Libin noted that after the first month, only 0.5 percent of users paid for the service; however, this rate gradually increased. By month thirty-three, 11 percent of users had started paying. At month forty-two, a 8 remarkable 26 percent of customers were paying for something they had previously used for free.” ( :16)

“”For example, after 20 days with a cycle time of two days, you will have 20,470 users,” Skok writes. “But if you halved that cycle time to one day, you would have over 20 million users!” ( :17)

“A classic paper by John Gourville, a professor of marketing at Harvard Business School, stipulates that “many innovations fail because consumers irrationally overvalue the old while companies irrationally overvalue the new.”” ( :17)

“11 This layout prevented typists from jamming the metal type bars of early machines. This physical limitation is an anachronism in the digital age, yet QWERTY keyboards remain the standard despite the invention of far better layouts. Professor August Dvorak’s keyboard design, for example, placed vowels in the center row, increasing typing speed and accuracy. Though patented in 1932, the Dvorak Simplified Keyboard was written off. QWERTY survives due to the high costs of changing user behavior.” ( :18)

“Like flossing, frequent engagement with a product— especially over a short period of time—increases the likelihood of forming new routines.” ( :19)

“Sometimes a behavior does not occur as frequently as flossing or Googling, but it still becomes a habit. For an infrequent action to become a habit, the user must perceive a high degree of utility, either from gaining pleasure or avoiding pain.” ( :19)

“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).” ( :20)

“”Are you building a vitamin or painkiller?” is a common, almost clichéd question many investors ask founders eager to cash their first venture capital check. The correct answer, from the perspective of most investors, is the latter: a painkiller. Likewise, innovators in companies big and small are constantly asked to prove their idea is important enough to merit the time and money needed to build it.” ( :21)

“Painkillers solve an obvious need, relieving a specific pain, and often have quantifiable markets.” ( :21)

“But like so many innovations, we did not know we needed them until they became part of our everyday lives. Before making up your mind on the vitamin versus painkiller debate for some of the world’s most successful tech companies, consider this idea: A habit is when not doing an action causes a bit of pain.” ( :22)

“Habit-forming technologies are both. These services seem at first to be offering nice-to-have vitamins, but once the habit is established, they provide an ongoing pain remedy.” ( :22)


2: Trigger


“Triggers come in two types: external and internal.” ( :27)

“External triggers are embedded with information, which tells the user what to do next.” ( :27)

“Instead, because this is an important account alert e-mail, Mint has” ( :28)

“Instead, because this is an important account alert e-mail, Mint has” ( :28)

“reduced the available actions to a single click: logging in to view and fix your account.” ( :29)

“The only purpose for these common visual triggers is to prompt the user to action. As a readily accepted aspect of interface design, these calls to action don’t need to tell people how to use them; the information is embedded.” ( :29)

“Because paying for reengagement is unsustainable for most business models, companies generally use paid triggers to acquire new users and then leverage other triggers to bring them back.” ( :30)

“For earned triggers to drive ongoing user acquisition, companies must keep their products in the limelight—a difficult and unpredictable task.” ( :30)

“blasting a message to their social networks, they may see some initial growth, but it comes at the expense of users’ goodwill and trust. When people discover they’ve been duped, they vent their frustration and stop using the product.” ( :30)

“When users form habits, they are cued by a different kind of trigger: internal ones.” ( :31)

“Internal triggers manifest automatically in your mind. Connecting internal triggers with a product is the brass ring of consumer technology.” ( :31)

“can take weeks or months of frequent usage for internal triggers to latch onto cues. New habits are” ( :32)

“sparked by external triggers, but associations with internal triggers are what keeps users hooked.” ( :33)

“Williams continued, “We often think the Internet enables you to do new things . . . But people just want to do the same things they’ve always done.” These common needs are timeless and universal.” ( :33)

“et talking to users to reveal these wants will likely prove ineffective because they themselves don’t know which emotions motivate them. People just don’t think in these terms.” ( :33)

“declared preferences—what they say they want—are far different from their revealed preferences—what they actually do.” ( :33)

“actually do (watch cat videos) rather than what they wish they did (produce cinema-quality home movies) it actually expands possibilities.”” ( :33)

“”[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.”” ( :33)


3: Action


“To initiate action, doing must be easier than thinking.” ( :38)

“To initiate action, doing must be easier than thinking. Remember, a habit is a behavior done with little or no conscious thought.” ( :38)

“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.” ( :38)

“The Fogg Behavior Model is represented in the formula B = MAT, which represents that a given behavior will occur when motivation, ability, and a trigger are present at the same time and in 1 sufficient degrees. If any component of this formula is missing or inadequate, the user will not cross the “Action Line” and the behavior will not occur. Let’s walk through an example Fogg uses to explain his model. Imagine a time when your mobile phone rang but you didn’t answer it. Why not? Perhaps the phone was buried in a bag and therefore difficult to reach. In this case your inability to easily answer the call inhibited the action. Your ability was limited.” ( :38)

“Maybe you thought the caller was a telemarketer or someone else you did not want to speak to. Your lack of motivation influenced you to ignore the call. It is possible that the call was important and within arm’s reach, but the ringer on your phone was silenced. Despite having both a strong motivation and easy access to answer the call, it was completely missed because you never heard it ring—in other words, no trigger was present.” ( :39)

“motivation as “the energy for action.”” ( :39)

“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.” ( :39)

“While internal triggers are the frequent, everyday itch experienced by users, the right motivators create action by offering the promise of desirable outcomes (i.e., a satisfying scratch).” ( :41)

“In line with Hauptly’s assertion, as the steps required to get something done (in this case to get online and use the Internet) were removed or improved upon, adoption increased.” ( :42)

“Evan Williams, cofounder of Blogger and Twitter, echoes Hauptly’s formula for innovation when he describes his own approach to building two massively successful companies: “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.”” ( :43)

“According to the Fogg Behavior Model, ability is the capacity to do a particular behavior.” ( :44)

“6 Fogg describes six “elements of simplicity”—the factors that influence a task’s difficulty. These are: 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—according to Fogg, “How much the action matches or disrupts existing routines.”” ( :44)

“Simply put, Google reduced the amount of time and the cognitive effort required to find what the user was looking for.” ( :48)

“Simply put, Google reduced the amount of time and the cognitive effort required to find what the user was looking for. The company continues to relentlessly improve its search engine by finding new ways to remove whatever might be in the user’s way—no matter how seemingly trivial.” ( :48)

“first, motivation or ability? Where is your time and money better spent? The” ( :49)

“answer is always to start with ability.” ( :50)

“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.” ( :50)

“For example, every Economics 101 student learns that as prices decrease, consumers purchase more—in Fogg’s terms, an example of increasing ability by decreasing price.” ( :53)

“Although the cookies and jars were identical, participants valued the ones in the near-empty jar more highly. The appearance of scarcity affected their perception of value.” ( :53)

“Results remained consistent with the scarcity heuristic. The group left with only two cookies rated them to be more valuable, while those experiencing sudden abundance by going from two to ten actually valued the cookies less. In fact, they valued the cookies even lower than people who had started with ten cookies to begin with.” ( :54)

“The mind takes shortcuts informed by our surroundings to make quick and sometimes erroneous judgments.” ( :54)

“After surveying other options I noticed a package of five Fruit of the Loom brand undershirts selling for $34. After doing some quick math I discovered that the undershirts not on sale were actually cheaper per shirt than the discounted brand’s package.” ( :55)

“People often anchor to one piece of information when making a decision.” ( :55)

“One group was given a blank punch card with eight squares; the other was given a punch card with ten squares that came with two free punches. Both groups still had to purchase eight car washes to receive a free wash; however, the second group of customers—those that were given two free punches—had a staggering 82 percent higher completion rate.” ( :55)

“The study demonstrates the endowed progress effect, a phenomenon that increases motivation as people believe they are nearing a goal.” ( :55)

“LinkedIn and Facebook utilize this heuristic to encourage people to divulge more information about themselves when completing their online profiles. On LinkedIn every user starts with some semblance of progress (figure 19). The next step is to “Improve Your Profile Strength” by supplying additional information. As users complete each step, the meter incrementally shows the user is advancing. Cleverly, LinkedIn’s completion bar jump-starts the perception of progress and does not include a numeric scale. For the new user, a proper LinkedIn profile does not seem so far away. Yet even the “advanced” user still has additional steps she can take to inch toward the final goal.” ( :56)

“Which resources are limiting your users’ ability to accomplish the tasks that will become habits? Time Brain cycles (too confusing) Money Social deviance (outside the norm) Physical effort Non-routine (too new)” ( :57)


4: 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.” ( :60)

“Without variability we are like children in that once we figure out what will happen next, we become less excited by the experience.” ( :60)

“Our brains are adapted to seek rewards that make us feel accepted, attractive, important, and included.” ( :62)

“Stack Overflow devotees write responses in anticipation of rewards of the tribe. Each time a user submits an answer, other members have the opportunity to vote the response up or down. The best responses percolate upward, accumulating points for their authors” ( :63)

“The need to acquire physical objects, such as food and other supplies that aid our survival, is part of our brain’s operating system.” ( :65)

“We are driven to conquer obstacles, even if just for the satisfaction of doing so. Pursuing a task to completion can influence people to continue all sorts of behaviors.” ( :68)

“The rewards of the self are fueled by “intrinsic motivation” as highlighted by the work of Edward Deci and Richard Ryan. Their self-determination theory espouses that people desire, among other things, to gain a sense of competency. Adding an element of mystery to 19 this goal makes the pursuit all the more enticing.” ( :68)

“At first Mahalo garnered significant attention and traffic. At its high point 14.1 million users 21 worldwide visited the site monthly. But over time, users began to lose interest. Although the payout of the bounties was variable, somehow users did not find the monetary rewards enticing enough.” ( :73)

“Ultimately, the company found that people did not want to use a Q&A site to make money. If the trigger was a desire for monetary rewards, users were better off spending their time earning an hourly wage. And if the payouts were meant to take the form of a game, like a slot machine, then the rewards came far too infrequently and were too small to matter.” ( :73)

“Quora’s social rewards have proven more attractive than Mahalo’s monetary rewards. Only by understanding what truly matters to users can a company correctly match the right variable reward to their intended behavior.” ( :73)

“When there is a mismatch between the customer’s problem and the company’s assumed solution, no amount of gamification will help spur engagement.” ( :73)

“The magic words the researchers discovered? The phrase “But you are free to accept or refuse.”” ( :74)

“The researchers believe the phrase “But you are free” disarms our instinctive rejection of being told what to do. If you have ever grumbled at your mother when she tells you to put on a coat or felt your blood pressure rise when your boss micromanages you, you have experienced what” ( :74)

“psychologists term reactance, the hair-trigger response to threats to your autonomy.” ( :75)

“Here are two examples to make the case that they do—but naturally, you are free to make up your own mind.” ( :75)

“However, it leverages familiar behaviors users want to do, instead of have to do.” ( :75)

“Social acceptance is something we all crave, and Fitocracy leverages the universal need for connection as an on-ramp to fitness, making new tools and features available to users as they develop new habits.” ( :76)

“Unfortunately, too many companies build their products betting users will do what they make them do instead of letting them do what they want to do.” ( :76)

“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.” ( :76)

“By maintaining the users’ freedom to choose, products can facilitate the adoption of new habits and change behavior for good.” ( :76)

“In a phenomenon termed experience-taking, researchers have shown that people who read a story about a character actually feel what the protagonist is feeling” ( :77)

“By March 2012 Zynga’s stock was flying high and the company was valued at over $10 billion. Yet by November of that same year, the stock was down over 80 percent. It turned out that Zynga’s new games were not really new at all. The company had simply done retreads of FarmVille; players had lost interest and investors followed suit. What was once novel and intriguing became rote and boring. The -Villes had lost their variability and with it, their viability.” ( :77)

“Online games like FarmVille suffer from what I term finite variability—an experience that becomes predictable after use.” ( :77)

“Experiences with finite variability become less engaging because they eventually become predictable.” ( :78)

“For example, games played to completion offer finite variability, while those played with other people have higher degrees of infinite variability because the players themselves alter the gameplay throughout. World of Warcraft, the world’s most popular massively multiplayer online role-playing game, still captures the attention 31 of more than 10 million active users eight years after its release. FarmVille is played mostly in solitude, but World of Warcraft is frequently played with teams; it is the hard-to-predict behavior of other people that keeps the game interesting.” ( :78)

“As described, the most habit-forming products and services utilize one or more of the three variable rewards types: the tribe, the hunt, and the self. In fact, many habit-forming products offer multiple variable rewards.” ( :78)

“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 hunt is the search for material resources and information. Rewards of the self is the search for intrinsic rewards of mastery, competence, and completion.” ( :79)

“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.” ( :80)


5: Investment


“A psychological phenomenon known as the escalation of commitment has been shown to make our brains do all sorts of funny things.” ( :82)

“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.” ( :83)

“IKEA puts its customers to work. It” ( :83)

“turns out there’s a hidden benefit to making users invest physical effort in assembling the product—by asking customers to assemble their own furniture, Ariely believes they adopt an irrational love of the furniture they built, just like the test subjects did in the origami experiments.” ( :84)

“A team of researchers asked a group of suburban residents to place large, unsightly signs in front 5 of their homes that read CAREFULLY. Two groups were tested. In the first group only 17 percent DRIVE of the subjects agreed to the request, while 76 percent of those in the second group agreed to post the ugly yard signs. What was the cause of this huge discrepancy? The groups were identical except for one factor. Those in the second group were approached two weeks prior to the yard sign request and asked to place a much smaller, three-inch sign that read in their windows. BE A SAFE DRIVER” ( :84)

“a hungry fox encounters grapes hanging from a vine. The fox desperately wants the grapes. Yet as hard as he tries, he cannot reach them. Frustrated, the fox decides the grapes must be sour and that therefore he would not want them anyway.” ( :84)

“These tendencies of ours lead to a mental process known as rationalization, in which we change our attitudes and beliefs to adapt psychologically.” ( :85)

“Mafia Wars was among the first games to utilize information about players’ Facebook friends. “It’s not just a virtual world anymore. It’s your real friends.” Schell said. “And you’re playing and it’s kind of cool . . . but then, hey, hey, my real friend is better than me. How can I remedy that? Well, I can play a long time or I could just put twenty dollars in—aha! It’s even better if that twenty dollars I put in validates something I know is true, that I am greater than my college roommate, Steve.”” ( :85)

“believe, ‘This must be worthwhile. Why? Because I’ve spent time on it!’ And therefore it must be worth me kicking in twenty dollars because look at the time I’ve spent on it. And now that I’ve kicked in twenty dollars, it must be valuable because only an idiot would kick in twenty dollars if it wasn’t.”” ( :85)


6: What Are You Going to Do with This?


“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)” ( :100)

“Maybe you felt a bit unsettled reading what seemed like a cookbook for mind control. If so, that is a very good thing.” ( :100)

“Chris Nodder, author of the book Evil by Design, writes, “It’s OK to deceive people if it’s in their best interests, or if they’ve given implicit consent to be deceived as part of a persuasive strategy.”” ( :101)

“The matrix seeks to help you answer not “Can I hook my users?” but instead “Should I attempt to?”” ( :102)

“When you create something that you would use, that you believe makes the user’s life better, you are facilitating a healthy habit. It is important to note that only you can decide if you would actually use the product or service, and what “materially improving the life of the user” really means in light of what you are creating.” ( :102)

“First, it is important to recognize that the percentage of users who form a detrimental dependency is very small.” ( :103)

“Creating a product that the designer does not believe improves users’ lives and that he himself would not use is called exploitation.” ( :105)

“In a satirical take on Zynga’s FarmVille franchise, Ian Bogost created Cow Clicker, a Facebook 11 game in which users did nothing but incessantly click on virtual cows to hear a satisfying moo. Bogost intended to lampoon FarmVille by blatantly implementing the same game mechanics and viral hacks he thought would be laughably obvious to users. But after the app’s usage exploded and some people became frighteningly obsessed with the game, Bogost shut it down, bringing on what he called the “Cowpocalypse.”” ( :105)


7: Case Study: The Bible App


“This is not surprising. The Fogg Behavior Model (see chapter 3) notes that for an action to occur, users must receive a trigger and have sufficient motivation and ability to complete it. If any of these elements are missing or inadequate at the moment the trigger arises, the action will not occur.” ( :108)


8: Habit Testing and Where to Look for Habit-Forming Opportunities


“I term Habit Testing. It is a process inspired by the “build, measure, learn” methodology championed by the lean start-up movement.” ( :114)

“First, define what it means to be a devoted user. How often “should” one use your product?” ( :114)

“”Instead of asking ‘what problem should I solve?’ ask ‘what problem do I wish someone else would solve for me?'”” ( :116)

“3 Buffer was founded in 2010 and is now used by over 1.1 million people. Its founder, Joel 4 Gascoigne, described the company’s inception in an interview. “The idea for Buffer came to me after I had been using Twitter for about 1.5 years. I had started to share links to blog posts and quotes I found inspiring, and I found that my followers seemed to really like these types of tweets. I would often get retweets or end up having a great conversation around the blog post or quote. That’s when I decided I wanted to share this kind of content more frequently, because the conversations being triggered were allowing me to be in touch with some super smart and interesting people.”” ( :116)

“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.” ( :116)

“In 1911 Ferdinand Foch” ( :117)

“In 1957 the editor of business books for Prentice Hall” ( :117)

“In 1995 Clifford Stoll wrote a Newsweek article, “The Internet? Bah!” in which he declared,” ( :117)

“Maples believes technology waves follow a three-phase pattern: “They start with infrastructure. Advances in infrastructure are the preliminary forces that enable a large wave to gather. As the wave begins to gather, enabling technologies and platforms create the basis for new types of applications that cause a gathering wave to achieve massive penetration and customer adoption. Eventually, these waves crest and subside, making way for the next gathering wave to take shape.” ( :118)

“For Instagram, the interface change was cameras integrated into smartphones. Instagram discovered that its low-tech filters made relatively poor-quality smartphone photos look great. Suddenly taking good pictures with your phone was easier; Instagram used its newly discovered insights to recruit an army of rabidly snapping users. With” ( :119)

Check out more book notes at How I Read 90 Books In The Past 2 Years By Reading 20 Pages A Day

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