Hooked: How to build Habit-Forming Products

Author: Nir Eyal with Ryan Hoover

Rating: ★★★★☆

Author: By: Nir Eyal with Ryan Hoover

Rating: ★★★★☆

Book Notes: Nir lays out the model for how to engage (or get them addicted?) to your app. It centers around the Hook model which is pretty much the same as any model associated with building a habit. You must create a Trigger, a simple action for them to engage with, then offer a variable reward and try to increase the liklihood of this loop by getting them to invest in the app. If you’re a first-time app builder then this is worth the read as it’ll provide a framework for your app ideas.

For some businesses, forming habits is a critical component to success, but not every business requires habitual user engagement.

Triggers cue the user to take action and are the first step in the Hook Model. Triggers come in two types — external and internal.

Refer to the answers you came up with in the last “Do This Now” section to complete the following exercises:

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
3. A trigger must be present to activate the behavior.

Fogg states that 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.


Fogg describes six “elements of simplicity” — the factors that influence a task’s difficulty. These are:

Action is the second step in The Hook. - The action is the simplest behavior in anticipation of reward. - As described by the Dr. BJ Fogg’s Behavior Model:

Refer to the answers you came up with in the last “Do This Now” section to complete the following exercises:

Variable Reward is the third phase of the Hook Model, and there are three types of variable rewards: tribe, hunt and self.

A team of researchers asked a group of suburban residents to place large, unsightly signs in front of their homes which read “Drive Carefully.”civ Two groups were tested. In the first group, only 17 percent 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, with the exception of 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 with the words, “Be a safe driver,” in their window.

Nearly everyone who was asked to place the smaller message agreed. When the researchers returned two weeks later, a whopping majority of these residents willingly replaced the small sign with the large one on their front lawns. The homeowner’s greater willingness to place the large, obtrusive sign on their lawns after agreeing to the smaller ones 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.

In the story, 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 can not 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 call “cognitive dissonance.”

The Investment Phase is the fourth step in the Hook Model.

The Hook Model helps the product designer generate an initial prototype for a habit-forming technology. It also helps uncover potential weaknesses in an existing product’s habit-forming potential.