Facebook. Twitter. Instagram. World of Warcraft. Angry Birds. The most successful tech products have one thing in common: They’re addictive. And users don’t get hooked by accident. Just ask Nir Eyal. A Bay Area entrepreneur turned desire guru, Eyal has worked with some of the top tech firms in Silicon Valley, teaching them how to apply the system he developed for engineering habit-forming apps, services, and games. His blog, Nir and Far, has attracted tens of thousands of subscribers hungry for insights, and his writing has appeared in both the mass-market pages of Psychology Today and the insider club of TechCrunch. His inaugural Habit Summit, held last March on the Stanford campus, drew 400 participants. Eyal’s book, Hooked: How to Build Habit-Forming Products, self-published in January 2014, shot immediately to the top of Amazon’s product-design list. Penguin acquired it and released it in November.
At the heart of Eyal’s system is a four-step cycle he calls the Hook. These steps were derived from his observation of online products and services, as well as a wide range of psychological and neurological research, from B. F. Skinner to B. J. Fogg. The Hook, Eyal says, is the magic behind just about every icon of the consumer Internet, from Google to WhatsApp.
1 | TRIGGER
The process starts with a cue or stimulus. That’s an external trigger. It’s most effective if it arrives when the target is feeling some kind of discomfort (which Eyal calls an internal trigger), from which it can promise relief—like a Facebook message that happens to arrive in your inbox just when you’re feeling alone. “The more times users go through the Hook, the more the product forms an association with internal triggers like loneliness, boredom, or fear,” Eyal explains. “When we’re lonely, we turn to Facebook. When we’re feeling out of the loop, we turn to Twitter.”
You’re sitting at home on a Sunday afternoon, feeling lonely and wondering if everyone else had a better weekend. Your phone buzzes with a Facebook alert: You’ve been tagged in a photo taken at the party you went to on Friday. You log on to Facebook to check it out.
2 | ACTION
A behavior happens when a trigger coincides with both the motivation to take action and the ability to do so, says theorist B. J. Fogg. Say you’re expecting a phone call while in the middle of a business meeting; your motivation to answer is high, but your ability to answer is low, so when the phone rings you don’t pick up. Or you may be free to answer when your phone rings, but you notice that the incoming number is blocked—presumably by a telemarketer. Now your ability to answer is high but your motivation is low, and again you don’t answer. If a trigger consistently fails to initiate the desired behavior, habit designers should aim to boost the user’s ability, which is easier to influence than motivation.
You spend your lunch hour reading a newsletter that has arrived in your inbox. One story in particular catches your fancy, and at the bottom you see the message “Share with friends.” Clicking it automatically connects you to your Twitter account. The technology has made it so easy for you to tweet—increased your ability—that you take the action almost without thinking about it.
3 | REWARD
Rewards can come in an almost endless variety of forms, from receiving attention, acceptance, and appreciation (an obvious force in social networks) to gaining a sense of mastery and autonomy (thank you videogames and Words With Friends) to prizes like money and gift cards. One of the most powerful methods to amp up the anticipation and ultimate effect of a reward, B. F. Skinner found, is to make it unpredictable. A classic example is slot-machine gambling. The player never knows whether the next pull might bring a $5 win or a $50,000 jackpot. The unpredictability of the reward—and the randomness of its arrival—is a powerful motivator to pull the lever again and again.
You’re a software programmer and you’re active on Stack Overflow, the community site where volunteers post some 10,000 coding answers a day. Last week you saw a question about an interesting problem: Hitting the Clear button in a shopping app doesn’t empty the cart. You had recently solved this problem yourself, so you posted the code. Logging in now, you’re delighted to see that your reply has gotten 10 up-votes, way more than you expected. You beam with pride.
You’re sitting at your desk at the end of a workday when your phone chimes with a Snapchat notification. It’s from a colleague who’s on vacation: He’s sent you a photo of a brimming martini sitting next to a juicy steak. You have to reply, which is easy to do—just double-tap on the message and your phone’s camera is activated. You send your colleague a photo of a knish. You can’t wait to see what he sends back.
4 | INVESTMENT
This last stage of the process closes the loop by “loading the next trigger,” Eyal says. The key is for the user to contribute some element of their own—a tweet, a comment, a video—and for that, in turn, to set in motion a chain of events resulting in the delivery of the next trigger. Consider Instagram: You make an investment by posting a photo. Then, when a follower likes or comments on your contribution, the service sends a push notification triggering you to take yet another spin through the Hook. Investment can also engage what behavioral economist Dan Ariely calls the Ikea effect: Contribute to the creation of something and you value it more, whether it’s a YouTube video of your kid’s recital or a post on Pinterest.