When readers see their progress tracked through daily streaks or earn badges...

https://www.tumblr.com/gladlyradiantsphinx/819598402316812288/why-do-i-feel-like-content-is-engineered-now

When readers see their progress tracked through daily streaks or earn badges for exploring new topics, they feel a sense of momentum. Personalization turns a cluttered feed into a curated space that actually reflects their interests