T-Mobile has really been stepping up the rhetoric against Sprint since the backroom acquisition deal allegedly fell through a few weeks ago. T-Mobile's latest promotion takes direct aim at the Now Network, but it targets the other big carriers too. Starting next week, if you bring a friend over to T-Mobile on a Simple Choice plan, you and they both get a free upgrade to unlimited LTE for one year. Also, there will be awkward dancing, if T-Mobile's promo image is to be believed.
The unlimited LTE plan (with talk and text) on T-Mobile is $80 per month, while the cheapest one is $50 for 1GB of LTE. Presumably someone could sign up under the cheapest plan, and get the unlimited data bucket for a year at no extra cost. That's a solid value that basically saves $30 each month, assuming you take advantage of that data. You will need to enter your friend's ported number on T-Mobiles referral page within 30 days to be verified, and it won't go into effect until the end of the following billing cycle. If you're already on unlimited data, T-Mobile will add a $10 bill credit to your account.
Sprint is taking the brunt of T-Mobile's snide aggression in the announcement for this promotion. I imagine that's because T-Mobile feels it can push past Sprint into the third-place spot rather easily. The unlimited data deal works with converts from other carriers too. The deal starts August 29th.