Hooked: How to Build Habit-Forming Products

Hooked: How to Build Habit Forming Products (2014) is a best bestselling book by Israeli-American author Nir Eyal, who draws upon his work a startup founder, gaming and ad designer, consultant, and professor of consumer psychology. In Hooked, Eyal coaches businesses and tech designers on how to increase user engagement through habit-forming design. He argues that, for modern tech companies, success is not only dependent on their total number of users, but how frequently those users engage with their product. It is essential for the financial success of these companies to “hook” consumers to integrate products into their everyday lives. Eyal’s “Hook Model” is a guide for designing products that exploit people’s tendencies to form habits as a response to everyday routines and feelings.

This guide refers to the Kindle edition of this book.

Summary

In Eyal’s introduction he explains that habits are behaviors which people perform so frequently they become subconscious; they are usually integrated into an everyday routine or an automatic response to a certain feeling. By understanding this part of human psychology, app designers can make their products more habit- forming by exploiting people’s “internal triggers” which prompt them to use certain products frequently (3).

Eyal provides a brief overview of his four-step “Hook Model” of user engagement. In the first step the user experiences a “Trigger,” which prompts them to perform a certain “Action,” bringing them to a “Variable Reward,” and finally, to the “Investment Phase” (8-9). The more customers experience this cycle the more likely they are to form a habit around using a product.

In his first chapter, Eyal explains that companies benefit enormously from frequent users, since habitual use increases each customer’s “Lifetime Value,” or the amount of money a company can make from one individual (19). Companies with habitual users can increase their prices without losing many customers and enjoy free word-of-mouth marketing as users recommend the product to their social circle. Two factors inform the habit-forming potential of a product: frequency and usefulness. If a customer perceives a product as being very useful and needs to use it frequently there is a high chance they will form a habit of using it.

In Chapter 2, Eyal explores the first step of his “Hook Model,” the “Trigger.” He explains that triggers, which can be external or internal, prompt people to begin a certain behavior. Companies often employ external triggers such as advertisements, viral videos, strong reviews, social media activity, and company newsletters. These external triggers should be seductive enough to prompt the user to use the product repeatedly, thereby creating a habit and “internal triggers” in their own mind which prompt them to return to the product again, even in the absence of external triggers (47). Negative emotions such as boredom, loneliness, or fear of missing out are often effective internal triggers which re-hook users.

In Chapter 3, Eyal argues that an appealing trigger, sufficient motivation, and ease of access are the three main things that drive users to engage with a product. Eyal coaches the reader to simplify their product design to increase easy useability. He explains that humans use “heuristics,” or mental shortcuts, to make quick decisions. These include the “scarcity effect,” “framing effect,” “anchoring effect,” and “endowed progress effect,” all of which can be utilized within product design to coax users to take a certain action.

In Chapter 4, Eyal argues that products must reward users for their engagement. Eyal explains the three types of variable rewards: “the tribe,” “the hunt,” and “the self,” and argues that products must offer at least one of these to the user (99). Ideally, rewards should be variable rather than predictable, as this tends to keep people interested in the product. Eyal explains the final stage of his “Hook Model”: Investment. In this stage users are asked to invest a small amount of data, money, time, skill-building, or other actions into the product in order to make it more usable or personalized to them.

Eyal claims that people generally expect to put some work into their relationships and extend to machines and digital products; companies can thus encourage users to invest more time and energy into using their service. Eyal asks the reader to consider how they could ask their users to invest a small amount of work into using their product and therefore add value “in the form of content, data, followers, reputation, or skill” (161). This final stage should set up the next “trigger” for the user; for instance, if a user invests time amassing friends or followers, they are more likely to respond to notifications about activity and return to the site.

In Chapter 6, Eyal explores the ethical issues inherent in persuasive design. He explains his own approach to analyzing whether an idea is moral or not; he calls it the “Manipulation Matrix.” The Matrix consists of two questions: Would the designer use this product herself, and will this product improve the user’s life? Eyal encourages the reader to be a “Facilitator,” the kind of professional who can genuinely answer yes to both questions. Other combinations result in less ethical roles such as being a “Peddler,” “Entertainer,” or, worst of all, a “Dealer.”

In the following chapter, Eyal explores another case study of the Hook Model in action as he analyzes the success of the Bible app. He explains how this app offers the user a persuasive trigger in daily notifications, many opportunities to take easy and rewarding actions, variable rewards in the form of congratulations and success tracking, and ways to invest in the app through bookmarking and notetaking. Eyal claims that this app is an example of an ethical product which is proven to be habit forming for users.

In his final chapter, Eyal instructs the reader to further develop their product using three steps: identifying how users engage with it, codifying this information to find out which users are habitual, and modifying their product to make it more habit- forming for other users, too. He claims that by reflecting on their own needs and interests designers can tap into what is missing from the market in order to create something truly useful and novel. He encourages the reader to think big and stay openminded about new types of services and opportunities as they design products.