The Hook Model
link to the page of Nir Eyal and the book
The Hook Model describes in 4 phases how the use of a product becomes an everyday habit. These 4 phases are trigger, action, variable reward and investment.
The trigger is the actuator of a behavior—the spark plug in the Hook Model. Triggers come in two types: external and internal.
Habit-forming technologies start by alerting users with external triggers like an email, a link on a website, or the app icon on a phone. By cycling continuously through these hooks, users begin to form associations with internal triggers, which become attached to existing behaviors and emotions. Soon users are internally triggered every time they feel a certain way. The internal trigger becomes part of their routine behavior and the habit is formed.
For example, suppose Barbra, a young lady in Pennsylvania, happens to see a photo in her Facebook news feed taken by a family member from a rural part of the state. It’s a lovely photo and since she’s planning a trip there with her brother Johnny, the trigger, intrigues her.
After the trigger comes the intended action. Here, companies leverage two pulleys of human behavior – motivation and ability. To increase the odds of a user taking the intended action, the behavior designer makes the action as easy as possible, while simultaneously boosting the user’s motivation. This phase of the Hook draws upon the art and science of usability design to ensure that the user acts the way the designer intends.
3. Variable Reward
What separates Hooks from a plain vanilla feedback loop is their ability to create wanting in the user.
Feedback loops are all around us, but predictable ones don’t create desire. The predictable 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—say a different treat magically appears in your fridge every time you open it—and voilà, intrigue is created. You’ll be opening that door like a lab animal in a Skinner box.
Variable schedules of rewards are one of the most powerful tools that companies use to hook users. Research shows that levels of dopamine surge when the brain is expecting a reward, just ask any primate. Introducing variability multiplies the effect, creating a frenzied hunting state, activating the parts associated with wanting and desire. Although classic examples include slot machines and lotteries, variable rewards are prevalent in habit-forming technologies as well.
The last phase of the Hook is where the user is asked to do a bit of work. This phase has two goals, as far as the behavior engineer is concerned. The first is to increase the odds that the user will make another pass through the Hook when presented with the next trigger. Second, now that the user’s brain is swimming in dopamine from the anticipation of reward in the previous phase, it’s time to pay some bills.
The investment generally comes in the form of asking the user to give some combination of time, data, effort, social capital, or money.
But unlike a sales funnel, which has a set endpoint, the investment phase isn’t about consumers opening up their wallets and moving on with their day. The investment implies an action that improves the service for the next go-around. Inviting friends, stating preferences, building virtual assets, and learning to use new features are all commitments that improve the service for the user. These investments can be
leveraged to make the trigger more engaging, the action easier, and the reward more exciting with every pass through the Hook.