CASE #001 Duolingo Retention 6 min read How Duolingo guilt-trips you into a 1,000-day streak Loss AversionGoal Gradient
CASE #002 Spotify Engagement 5 min read Why Spotify Wrapped turns your data into a flex Social ProofIKEA Effect
CASE #004 Notion Onboarding 6 min read How Notion stops the blank page from scaring you Zeigarnik EffectDefaults
CASE #007 LinkedIn Onboarding 6 min read The progress bar that quietly built LinkedIn Endowed ProgressGoal Gradient
CASE #008 Revolut Retention 5 min read How Revolut turns your spending into a game Variable RewardSocial Proof
CASE #009 Calm Pricing 5 min read Why Calm makes the annual plan feel like a steal AnchoringDecoy Effect