The Hook Model was developed by Nir Eyal, author of Hooked: How to Build Habit-Forming Products. He believes that our most purchased and utilized products achieve that status because they become a part of habitual behaviors. As marketers, we can tap into that by understanding the cycle:

• Trigger: The beginning of the cycle is often an external trigger like a push notification. However, as the cycle continues, negative internal emotions become triggers as we attempt to lessen these negative emotions with an action.
• Action: The easier you make things to do, the more likely a person will do it. Habit-forming products make taking action painless and straightforward.
• Variable Reward: The anticipation of reward is a strong motivator. Variability increases anticipation, making prospects and customers more likely to take an action that warrants a reward.
• Investment: Creating an investment or “buy-in” for your customers makes it more difficult for them to step away from your product or service.