In the United States, TikTok claims 170 million users. But in China, about 700 million use the domestic version, Douyin, and 300 million scroll the headlines on Toutiao, a news app. Every video that ByteDance’s users watch or post gives the company another data point about how people use the internet.
For years, ByteDance has applied that wealth of information to make its apps more appealing, improving its ability to recommend…