I typically rack up about 50GB/month on t-mo. I opted out of binge so I get full hd across the board.
I get unlimited data, a flagship phone, insurance, 5 GB hotspot, upgrade every 6 months to a new phone for $50 and after taxes and fees my bill is like $87 bucks a month.
If do I think it should be opt in or out via a text message or something and t-mo could do better here but ultimately for people on a strict budget this is probably a win for them. For those who it's not, it's a mild nuisance to go log onto the website and opt out. Also, you can opt in and out as much as you want so you could binge watch Making a Murderer on your phone and then opt out and start watching video in HD against your 2 or 5 or 10GB cap.. then opt back in and binge watch Jessica Jones.