TikTok reached 1 billion monthly active users faster than any social media platform in history — including Facebook and Instagram — by solving a problem that its competitors had misdiagnosed for years. The problem was not that users lacked content. The problem was that users had to do work to find good content. TikTok's recommendation algorithm eliminated that work entirely, delivering a continuous stream of engaging videos to users who had provided almost no preference signals, based purely on watch time, replays, and scroll behavior. The platform launched internationally in 2017, merged with Musical.ly in 2018, and by September 2021 had crossed 1 billion monthly active users. ByteDance, the Chinese parent company founded by Zhang Yiming in 2012, has never disclosed TikTok's revenue separately — third-party estimates suggest approximately $120 billion in 2024, up from $80 billion in 2022, though these figures conflate ByteDance's global revenue with TikTok's international operations. TikTok Shop launched in the United States in 2023, adding live commerce and in-app purchasing to a platform that had already established itself as a dominant force in consumer purchase discovery. The company acquired Musical.ly in 2017, Jukedeck (AI music generation) in 2019, and Pico (VR hardware) in 2021 — a portfolio of acquisitions that suggests strategic intent well beyond short-form video. The regulatory environment is the permanent overhead that no product improvement can address. India banned TikTok in 2020, eliminating approximately 200 million users with a single government order. The United States has cycled through attempted bans and forced divestiture legislation since 2020. Ireland fined TikTok €345 million in 2023 for violations of children's data protections under GDPR. Shou Zi Chew, who became CEO in 2021, has spent a significant portion of his tenure testifying before legislatures rather than operating the product.