Hooked: How to Build Habit-Forming Products

by Nir Eyal

The power of commitment makes some people play video games until they keel over and die.1 It is used to influence people to give more to charity.2 It has even been used to coerce prisoners of war into switching allegiances.3 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.

those who made their own origami animals valued their creation five times higher than the second group’s valuation, and nearly as high as the expert-made origami values (figure 28). In other words, those who invested labor associated greater value with their paper creations simply because they had worked on them. Ariely calls this the IKEA effect.

Unlike its competitors who sell preassembled merchandise, IKEA puts its customers to work. It 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. Businesses that leverage user effort confer higher value to their products simply because their users have put work into them. The users have invested in the products through their labor.

We Seek to Be Consistent with Our Past Behaviors

The homeowners’ greater willingness to place the large, obtrusive sign on their lawns after agreeing to the smaller one demonstrates the impact of our predilection for consistency with our past behaviors. Little investments, such as placing a tiny sign in a window, can lead to big changes in future behaviors.

We Avoid Cognitive Dissonance

In a classic Aesop’s fable, a hungry fox encounters grapes h...

hungry fox encounters grapes hanging...

the grapes must be sour

The fox comforts himself by changing his perception of the grapes because it is too uncomfortable to reconcile the thought that the grapes are sweet and ready for the taking, and yet he cannot have them. To reconcile these two conflicting ideas, the fox changes his perception of the grapes and in the process relieves the pain of what psychologists term cognitive dissonance.

Unlike in the action phase of the Hook discussed in chapter 3, investments are about the anticipation of longer-term rewards, not immediate gratification.

In the investment phase, however, asking users to do a bit of work comes after users have received variable rewards, not before.

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.

Every time users of Apple’s iTunes add a song to their collection, they are strengthening ties to the service. The songs on a playlist are an example of how content increases the value of a service. Neither iTunes nor their users created the songs, yet the more content users add, the more valuable the music library becomes

On LinkedIn the user’s online résumé embodies the concept of data as stored value. Every time job seekers use the service, they are prompted to add more information. The company found that the more information users invested in the site, the more committed they became to it.

“If we could get users to enter just a little information, they were much more likely to return.” The tiny bit of effort associated with providing more user data created a powerful hook to bring people back to the service.

Collecting people to follow on Twitter, as well as collecting followers, provides tremendous value and is a key driver of what keeps Twitter users hooked

From the follower side of the equation, the more Twitter users curate the list of people they follow, the better the service will be at delivering interesting content.

For the tweeter seeking followers, the more followers one has, the more valuable the service becomes as well.

Content creators on Twitter seek to reach as large an audience as possible. The only way to legitimately acquire new followers is to send tweets others think are interesting enough to warrant following the sender. Therefore, to acquire more followers, content creators must invest in producing more—and better—tweets. The cycle increases the value of the service for both sides the more the service is used. For many users, switching services means abandoning years of investment and starting over. No one wants to rebuild a loyal following they have worked hard to acquire and nurture.

Reputation is a form of stored value users can literally take to the bank. On online marketplaces such as eBay, TaskRabbit, Yelp, and Airbnb, people with negative scores are treated very differently from those with good reputations. It can often be the deciding factor in what price a seller gets for an item on eBay, who is selected for a TaskRabbit job, which restaurants appear at the top of Yelp search results, and the price of a room rental on Airbnb.

Reputation makes users, both buyers and sellers, more likely to stick with whichever service they have invested their efforts in to maintain a high-quality score

Investing time and effort into learning to use a product is a form of investment and stored value.

Adobe Photoshop is the most widely used professional graphics editing program in the world. The software provides hundreds of advanced features for creating and manipulating images. Learning the program is difficult at first, but as users become more familiar with the product—often investing hours watching tutorials and reading how-to guides—their expertise and efficiency using the product improves. They also achieve a sense of mastery (rewards of the self, as discussed in chapter 4). Unfortunately for the design professional, most of this acquired knowledge by users does not translate to competing applications. Once users have invested the effort to acquire a skill, they are less likely to switch to a competing product.

Just as in the action phase described in chapter 3, to achieve the intended behavior in the investment phase, the product designer must consider whether users have sufficient motivation and ability to engage in the intended behavior.

If users are not doing what the designer intended in the investment phase, the designer may be asking them to do too much.

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

Each photo or video sent contains an implicit prompt to respond; the Snapchat interface makes returning a pic incredibly easy by twice tapping the original message to reply. The self-destruct feature encourages timely responses, leading to a back-and-forth relay that keeps people hooked into the service by loading the next trigger with each message sent.

The Hook Model is designed to connect the user’s problem with the designer’s solution frequently enough to form a habit.

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.

Creating a product that the designer does not believe improves users’ lives and that he himself would not use is called exploitation

changing the order of the Bible by placing the more interesting sections up front and saving the boring bits for later increased completion rates. Furthermore, daily reading plans are kept to a simple inspirational thought and a few short verses for newcomers. The idea is to get neophytes into the ritual for a few minutes each day until the routine becomes a facet of their everyday lives.

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

“Who are the product’s habitual users?”

define what it means to be a devoted user. How often “should” one use 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.

You are looking for a Habit Path—a series of similar actions shared by your most loyal users.

in its early days, Twitter discovered that once new users followed thirty other members, they hit a tipping point that dramatically increased the odds they would keep using the site.

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

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.

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.

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.”9 Entrepreneurs looking for windows of opportunity would be wise to consider Maples’s metaphor.

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

The creation of a new infrastructure often opens up unforeseen ways to make other actions simpler or more rewarding. For example, the Internet was first made possible because of the infrastructure commissioned by the U.S. government during the cold war. Next, enabling technologies such as dial-up modems, followed by high-speed Internet connections, provided access to the web. Finally, HTML, web browsers, and search engines—the application layer—made browsing possible on the World Wide Web. At each successive stage, previous enabling technologies allowed new behaviors and businesses to flourish.

Subsequently, when the effort required to accomplish an action decreases, usage tends to explode.

Apple and Microsoft succeeded by turning clunky terminals into graphical user interfaces (GUI) accessible by mainstream consumers.