C Spire's rolling data now covers shared data plans1
While T-Mobile's Data Stash took rolling data coast-to-coast, regional carrier C Spire was actually the first carrier to offer customers the ability to keep unused data and roll it over to use the following month. C Spire is now expanding the program for use on its most popular shared data plans. Those sharing 10GB, 15GB and 30GB of data will automatically be switched to a similar plan with rolling data. C Spire customers currently using other plans without shared data, can switch at no cost.
With the plan, unused data rolls over to the following month to be shared by all of the plan's users. There are a few differences between T-Mobile's Data Stash, AT&T's Rollover Data and C Spire's rolling data. T-Mobile stakes users to a 10GB stash which customers must eat through before unused data rolls over. C Spire does not provide an initial stake, so data rolls over after the first month. One caveat. The amount of data that can be rolled over each month is limited to the amount of data contracted for. So if you pay for 10GB, that is the most amount of unused data that can be pushed forward to the next month, regardless of how much unused data you've banked over a period of months.
There is no time restriction on using C Spire's rolling data, unlike AT&T which requires customers to use up all Rollover Data in the month that it is pushed to, or else it will expire. T-Mobile's unused data must be used within a rolling 12 month period or it expires.
C Spire offers individual plans with rolling data for as low as $40 a month ($65 with a subsidized phone) for unlimited talk, text and 2GB of data. $55 a month ($80 with a subsidized phone) gets you 4GB of data and $65 monthly ($90 with a subsidized phone) gives you a 6GB data allowance. Depending on the number of lines and whether you buy a subsidized handset, shared data plans start as low as $110 for unlimited talk, text and 10GB of data (over 2 lines), and go as high as $190 a month for 30GB of shared data (over 4 lines).
C Spire's rolling data plan also includes smartphone tethering, and international text messaging to more than 140 countries.
source: CSpire via AndroidCentral