Create a four-step hook model with your product.

These are the basics of the hook model. If you want to create a product that will be addictive like Pinterest, Instagram or Facebook, you should follow these steps. In the next habit ideas, you will discover more details about each of these steps.

1. What’s the external trigger? What’s the internal trigger?
   First, your product needs an external trigger, such as an email or push notification. When users have used your app for a while, they should develop an internal trigger.

2. What action you want your user to do?
   The action will lead to a reward. But before the reward, the user must do an action.

3. What’s the variable reward?
   Predictable rewards do not work. A variable reward is the most important element of this model—it creates a dopamine spike.

4. What’s the investment?
   If we put some investment to the product, we will be more connected to it.