Owned audience

A subscriber count is permission to be recommended. An email address is a way to arrive. That difference is the whole term, and it shows up whenever a platform changes what it surfaces, restricts a channel, or loses an account to a hijacked login, because none of that touches a list you exported and kept. Discord servers, SMS lists and RSS feeds sit in the same family to varying degrees, though each still has an owner who is not you. Even email depends on inbox providers agreeing your mail is wanted.