AT&T mobile customers can watch AT&T-owned HBO Max without fearing any impact on their data allowances, despite the fact competing services like Amazon Prime Video, Disney+, Hulu, and Netflix will not be given similar treatment.

The Verge confirmed with AT&T that customers with AT&T mobile service can watch an unlimited amount of HBO Max and not exceed data allowances or the soft cap of 22-50 GB a month that unlimited use plan customers have.

The practice of exempting some content from data caps is known as “zero rating” and critics of the practice contend it is an “end run” around net neutrality. AT&T defends itself claiming HBO Max is paying AT&T to sponsor customer usage.

“According to an AT&T executive familiar with the matter, HBO Max is using AT&T’s ‘sponsored data’ system, which technically allows any company to pay to excuse its services from data caps,” according to the story in The Verge. “But since AT&T owns HBO Max, it’s just paying itself: the data fee shows up on the HBO Max books as an expense and on the AT&T Mobility books as revenue. For AT&T as a whole, it zeroes out. Compare that to a competitor like Netflix, which could theoretically pay AT&T for sponsored data, but it would be a pure cost.”

In short, AT&T is moving money from one of its pockets to the other, which may tangentially benefit AT&T mobile customers, but will also leave competing streaming services at a disadvantage, allowing AT&T to give preferential treatment to its own streaming service, which may discourage subscriptions to other services.

Ars Technica confirmed AT&T is not extending the data cap exemption to customers with AT&T DSL or Fiber service.