I’ve wondered if they don’t know the data. They can perfectly read the convo on your device, assign a category what you’re talking about and keeping that category. They don’t store, read, know the conversation, they only ‘analyze’ it. F.e. if you talk about planes they may assign a category travel and sell your profile to holiday companies?
I don’t know about this, I’m just thinking that’s how I’d do it if I ran an evil corp.