Hook Model Framework
Framework for building habit-forming products. Habits are not created — they are built through successive cycles through the Hook.
Core Principle
The Hook Model = a four-phase loop that connects the user's problem to your solution frequently enough to form a habit, moving usage from deliberate to automatic.
Trigger → Action → Variable Reward → Investment
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Scoring
Goal: 10/10. When reviewing or creating product engagement mechanics, rate them 0-10 based on adherence to the principles below. A 10/10 means full alignment with all guidelines; lower scores indicate gaps to address. Always provide the current score and specific improvements needed to reach 10/10.
The Four Phases
1. Trigger
Core concept: The actuator of behavior. Triggers are external (environment-driven: notifications, emails, ads) or internal (emotion-driven) — and the goal is to migrate users from external to internal triggers.
Why it works: Every habit starts with a cue. External triggers get users started, but internal triggers — boredom, loneliness, uncertainty, FOMO — drive unprompted usage; when your product becomes the automatic response to an emotion, you have a habit.
Key insights:
- Map your product to the specific negative emotion it resolves (boredom, loneliness, confusion, FOMO)
- Effective external triggers are well-timed, actionable, and lead to the simplest possible next action
- If users still need external prompts after ~30 days, no internal trigger has formed
Product applications:
| Context |
Application |
Example |
| Onboarding |
External triggers establish the first loop |
Welcome email with one clear action |
| Retention |
Map product to internal emotional trigger |
Instagram resolves boredom; Google resolves confusion |
| Re-engagement |
External triggers bridge gaps until habit forms |
Push: "Your friend just posted a photo" |
Copy patterns:
- "Don't miss what happened while you were away" (FOMO trigger)
- "Your friend just..." (social trigger bridging to internal)
- "Pick up where you left off" (routine trigger)
Ethical boundary: Never exploit vulnerable emotional states (depression, addiction, grief) — triggers should connect users to genuine value, not manufacture anxiety to drive opens.
See: references/triggers.md for trigger design, emotion mapping, and external-to-int
