Habits aren't built with features; they're built with behavior loops.
The Hook Model = Trigger → Action → Variable Reward → Investment. Miss one, the habit weakens.
External triggers (notifications, emails) should slowly become internal ones (emotion, boredom, curiosity).
The easier the action, the stronger the habit. Reduce friction ruthlessly.
Variable rewards work because the brain loves uncertainty more than consistency.
Users value what they invest in. Effort creates attachment.
Products that solve frequent, small problems win over "big but rare" solutions.
Ethical line is thin: design to help users, not hijack them.
Sticky takeaway: great products don't demand attention—they earn a place in a user's routine.