There are a few catches. You need to be on a One plan, of course, so your grandfathered plan won't cut it. Also, Netflix streaming on cellular still defaults to 480p -- you need to enable higher quality yourself. And there's a degree of lock-in involved. After all, if you switch carriers you're suddenly back to handling the Netflix bill yourself.

The network isn't shy about the reason for the move: this is a foil to AT&T's DirecTV Now and Verizon's Go90. T-Mobile claims it doesn't have an interest in snapping up a TV provider or internet service to offer video to its customers, and that many people would just want Netflix anyway. There's a degree of truth to that (there's a good chance you already have Netflix), but it's clear that T-Mobile's deal was born out of competitive pressure.