In short, AT&T will allow providers to subsidize the delivery of their content. This is being framed as a benefit to consumers since it could save them money. However:
The flip side of all this though is that content providers that can afford to pay for data costs will be able to entice more AT&T customers over to their services. Instead of encouraging more variety in content consumed it could reinforce the status quo as consumers naturally gravitate to the websites, apps and videos from the big internet brands willing to foot the data bill.
But one of the foundational principles of the internet is that it’s neutral, that no content is prioritized over other content. While AT&T stressed it won’t actually prioritize traffic in the Sponsored Data program — apps and content will work the same on the network no matter who’s footing the data bill — this type of program creates a kind of de facto hierarchy from the consumer’s standpoint. If all other things are equal, why not watch the video or use the app that doesn’t drain your data plan?
Looks to me like AT&T has found a good way to violate net neutrality while appearing to keep their hands clean.