Spotify keeps users engaged by syncing music across devices and using smart...

https://wiki-canyon.win/index.php/Designing_for_the_Reality_of_Mobile_Multitasking:_Stop_Overestimating_Your_User%27s_Attention_Span

Spotify keeps users engaged by syncing music across devices and using smart data to personalize every recommendation. They fold in gaming-style rewards and social features to make the app feel like a daily habit