Weeks after T-Mobile announced their “Data Stash” program which provides select data plans the ability to rollover, or “stash” data when unused. AT&T just revealed that they will be offering rollover data to their Mobile Share Value Customers. The Mobile Share Value plans allow multiple devices to share a pool of data ranging from 300 MB to 100 GB. AT&T’s Rollover Data does not apply to individual device plans.

There are some additional caveats to AT&Ts Rollover Data options. Rollover data is only good for one billing cycle. This effectively means that if you’re a data hungry family sharing 100 GB and you happen to have 1 GB left at the end of the pay period, the next month the family will share 101 GB. However, if that extra GB of data is not used during the next pay period, it will expire.

This plan does not offer near the flexibility of T-Mobile’s Data Stash program which not only can apply to individual lines on select plans, but also the “stash” of data is valid for up to a year before it expires; putting them light-years ahead of the competition. You can read more about T-Mobile’s Data Stash plans in their initial announcement. (We even have the first physical evidence of what the Data Stash physically looks like. Take a look!) It’s interesting to note a quote originally posted by CNET from industry analyst, Dawson, about some positive differences of AT&T’s Rollover Data versus T-Mobile’s Data Stash program:

AT&T’s version differs significantly from T-Mobile’s version. It’s less generous, with a single month of rollover rather than twelve months, but that should make it both easier for customers to keep track of and more manageable from a network load perspective. T-Mobile’s plan risks creating a situation similar to airline miles, where customers have a hard time keeping track of which miles (or Gigabytes of data) expire when.

It’s quite clear, however, that T-Mobile is quite confidence in their “Data Strong” network. By allowing unlimited music streaming and rollover data that doesn’t expire for a year, it appears that T-Mobile is prepared for a large influx in data use by their customers. While we’ve received no reports of network slow-down on T-Mobile’s network, time will tell whether this actually impacts their ability to manage network bandwidth.

AT&T’s new Data Rollover option will go into effect for both existing and new Mobile Share Plans starting January 25th.

What are your thoughts on AT&T’s rollover data plan? Do you think it’s overly stingy? Or are they just better planners than T-Mobile from a network bandwidth perspective? Let us know your thoughts in the comments below.