YouTube’s recommendation algorithm (70% of watch time) evolved from views (2005-2011) to watch time (2012) to engagement/retention (2016+). Creators obsess over “satisfying the algorithm” — CTR (click-through rate), AVD (average view duration), session time. The black box determines success/failure, spawning cottage industry of growth hackers, conspiracy theories, and creator anxiety. By 2023: algorithm favors shorts, long-form binge content, and whatever keeps users on platform longest, regardless of quality.
Sources: YouTube Creator Blog, algorithm researcher Guillaume Chaslot, creator testimonials