“The principle of novelty — every time you open Facebook or TikTok or Instagram you see something new. It's a little bit unexpected and that creates a feeling of reward for people and that's why they keep coming back to it.”

Novelty drives return visits more reliably than goals — show users something new every single open

Paloni built a pre-generative-AI content system at Welltory that produced effectively infinite variations of health insights — 45 message types each with near-infinite content permutations covering four Lord of the Rings volumes worth of text. The engineering effort was immense but solved the novelty problem: users never saw the same insight twice. With generative AI this is now tractable for any app. The core principle holds regardless of implementation: if opening your app feels like pulling the same lever every time, users stop pulling it.