So, we are talking about, on average, 7.2 GBytes of wireless data, 14 Gigabytes on the outside - spread over a number of years, and, at 200 MBytes/month, very low impact to their LTE networks.
Of course, nowadays, 200 MBytes lasts the average LTE user about 3-4 days, even if they are trying to be conservative.
I'm guessing there will be a lot of upselling ot bigger data packages.
What is cool about this, though - no contract, and you don't even have to be a TMobile customer.