Counterpart to
私域 (private domain).
公域流量 = traffic the platform controls and rents out: Tmall search results, Douyin's recommendation feed, Baidu ads. Brands pay per impression or click, and lose access the moment they stop paying. The whole point of building a
私域 is to escape
公域 dependence — once a customer is in your WeChat group, you reach them for free.