Cellular network T-Mobile tracks and sells which of their subscribers are business travelers for advertising purposes – but only subscribers using Android devices. Apple doesn’t allow T-Mobile to collect the data which makes this possible.

It’s being framed as T-Mobile “selling your app data to advertisers.” However that’s not quite right.

Instead the company that once fashioned itself the ‘un-carrier’ sells the ability to target its subscribers with ads based on their app usage. And T-Mobile knows which of their Android subscribers are business travelers:

T-Mobile uses network-level tools to track the apps that people use on their phones, and it then anonymizes and aggregates that data to lump you into various “personas,” or “cohorts” as other platforms would call it. For example, if you regularly use Expensify and airline apps on your phone, T-Mobile could identify you as a business traveler for advertising purposes.

In many ways this seems less intrusive than Google’s advertising, and your operating system and carrier (not to mention the government) have all tracked location data. They know when you drive to a medical office (sometimes a specialist in a particular area of medicine). They know if you visit a hotel in your home city and stay for just a couple of hours. They know who else spends time at your home. And we’ve accepted that with barely a shrug.

Tracking whether you’re using dating apps doesn’t seem like much of a stretch. Greater targeting based on the same data might let Bank of America target advertising to people using U.S. Bank’s app, or let the IRS target those with heavy usage of crypto apps but little tax return activity in that space.

Frankly I wouldn’t mind being targeted as a business traveler, the ads might be relevant and advertisers know I’m likely a good customer. (Well, maybe I’m not..) Airlines could target offers to heavy travel app users and a more granular version would let United make offers to heavy users of the American Airlines app, Marriott to make offers to users of the Hilton app, and this could be the future of status match.