If you look at a photo of a crowded New York City sidewalk at rush hour today, and compare it to one from, say, eight years ago, you’ll notice a big difference. While some of the people in the first photo may be looking down, in the photo taken today, everyone would be looking down at their hand, which holds the device that has effectively become an appendage: the smartphone, stuffed to the brim with social media apps like Facebook, Instagram, Twitter and Pinterest.

These apps, along with the gadget itself, have become helpful habits. And not by accident, either, argues Nir Eyal, author of a book that is sweeping both Silicon Valley and Silicon Alley: Hooked: How to Build Habit-Forming Products.

According to Eyal, these habit-forming products (and services) follow a human behavioral cycle—the Hook model—that has four distinct elements. It begins with a trigger, aka the user’s “itch” that needs to be scratched. That could be situations, routines, people, places and, most frequently, emotions, especially negative ones. For example, when we’re lonely, we check Facebook to connect with our friends.

Action follows, which Eyal defines as the simplest behavior in anticipation of a reward. Action requires both motivation, or energy for action, as well as the ability to perform that action. The motivation for Instagram, for instance, might be the fear of missing out, and the action of rapidly swiping through dozens of posts is the simple ability.

The third element, reward, is all about anticipation and can be supercharged by providing mystery and intrigue. The final element is investment, which is the notion of future rewards. Investments increase the likelihood of the next pass through the hook both by loading the next trigger of the hook as well as by storing value.

Given the importance of these elements to small-business owners looking to grow their customer base, I contacted Eyal to ask him a few questions about the Hook model.

Why does the world need more habit-forming products?

Habit-forming products can help people live better. Habits help us offload the cognitive effort to do the things we want to do but find too difficult. We are witnessing an explosion of companies trying to change user behavior in other ways—to help people live happier, healthier, richer and more connected lives.

Whenever I see “trigger and reward” mentioned in a conceptual model, I know I’m going to get behaviorist treatment in some form. How does the Hook Model differ from, say, the B.F. Skinner model and/or the B.J. Fogg model that you highlight in the book?

The Hook model is aimed at entrepreneurs and innovators, not scholars or psychologists. I’ve started two companies myself, and I know one of the most frustrating aspects of running a business is deciding what should and should not be part of your product or service. It helps to have a useful framework to take some of the guesswork out of product design.

To that end, I wanted to uncover deeper insights into the way consumers behave in order to help entrepreneurs and innovators understand what people want, even when customers can’t articulate those needs. I draw upon the work of some of the brightest minds in psychology but with the goal of giving readers practical insights, not just interesting dinner party conversation.

You say tech products rise in value while physical ones depreciate. So outside of the typical and successful digital products you cite—Instagram, Facebook, Twitter, Pinterest and Whatsapp—what non-digital companies have employed the Hook model to create habit-forming products or services?

Lots of offline products are habit-forming. The impulse to watch television at the same time of night, cheer for your local sports team every season, have your favorite cup of coffee from Starbucks each morning, visit your favorite store when you feel stressed or even attend religious services each week are all examples of behaviors we do, with little or no conscious thought, out of habit.

That said, not every business needs to form a user habit, but every business that forms a habit needs a hook. The bar is very high for habit-forming products—lots of things have to go right, and not many companies do it successfully. Of course, those who do it right create tremendous amounts of value. But even if your company doesn’t require a habit, understanding consumer psychology and applying even parts of the Hook [model] to your customer experience can improve your odds of success.

You write that a habit is a behavior done with little to no conscious thought and that habits demand frequency. From a habit-forming perspective, is there any hope at all for larger, more thoughtful and infrequent purchases or consumer actions that require a far greater investment than a social media app, such as buying a home or a car, or financial planning?

A large purchase such as buying a home or a car is not a habit. Those kinds of behaviors require a great deal of conscious thought and occur very infrequently—the antithesis of a habit. In those cases, companies should find ways to make other aspects of the customers’ experience a habit.

For example, I recently gave a talk to 750 real estate agents who are affiliated with a major brokerage firm. My advice to them was to find ways to engage their clients more frequently with small habits that eventually lead to buying or selling a home. The agents came up with all sorts of ideas for how they could form habits with their clients. One agent decided she would become the go-to source for information about weekly happenings in her community while another wanted to be the person potential clients called whenever they had anxiety about their personal finances.

You write that the Hook model explains the rationale behind the design of many successful habit-forming products and services we use daily, such as those mentioned earlier. Did any of the companies that created those products actually use the model as a blueprint for their efforts, or can you can share with OPEN readers an example of company that has used the model successfully from scratch?

Ryan Hoover, the co-author of Hooked, went on to start a company called Product Hunt shortly after we finished the book. Product Hunt is a place for product-loving enthusiasts to share and geek out about the latest mobile apps, websites, hardware projects and tech creations. It’s a very habit-forming product and has a great hook: People can submit links, upvote and comment. There’s a leader board effect, which is the incentive to keep coming back.

In your opinion, which of the four elements—trigger, action, reward or investment—is most commonly overlooked by designers, and why?

Each company trying to build a habit with its customers is unique and may therefore be missing or deficient in a different part of the Hook. They may not understand their internal trigger—the “itch” they’re scratching. They may not have a good way to send external triggers. The action may be too difficult, or the reward is not fulfilling. But perhaps the most frequently overlooked step of the Hook is the investment phase: Too many companies build their products to get prospects to just “check out”—they take their money and then send them off. I contend that many companies miss an opportunity to get customers to re-engage by not finding ways to help them “check in” frequently.

What’s the essence of, and motivation for, your message about the morality of manipulation?

I give a framework people can use to decide what kind of product is worth building a habit around. I offer two criteria: First, is the product or service something you believe materially improves people’s lives? Next, do you yourself use it? If the answer is yes to both questions, then you are what I call a “facilitator.” I’m not saying successful businesses can’t be built by people who answer no to either (or both) of those questions, but I believe that facilitators aren’t only on a sound, moral footing, but they also increase their odds of success. Many of the companies I profile in the book—including Facebook, Twitter, Instagram and Google—were founded by facilitators.

What’s the one thing you want readers to take away from Hooked?

The habits we form with the products we use every day is not a coincidence—it’s by design. We can use the psychology of habits for good.

You can follow Nir Eyal on Twitter @nireyal.

Republished from my OPEN column.