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Sprint Prepaid adds rollover data, with a catch

A new promotion lets prepaid customers bank up to 30GB of unused monthly data.

The LG Tribute is but one of multiple smartphones offered with Sprint Prepaid. CNET

Sprint is the latest wireless provider to dip its toes in the pool that is rollover data. Tuesday sees the carrier introducing a new feature, Monthly Rolling Data, for its Sprint Prepaid brand.

The new benefit comes with all Sprint Prepaid plans starting at $35 per month. For the sake of comparison, T-Mobile requires subscribers to purchase at least the $60 monthly plan (for 3GB) or more to qualify for its Data Stash.

Effective immediately, customers can now bank up to 30GB of unused data to tap at a later date. What's more, there is no expiration date, meaning that users can chip away at the accumulating data pool however they see fit.

On paper, at least, Sprint's Rolling Data also bests AT&T's Rollover Data program for its prepaid GoPhone service. AT&T's option only works on the $45 and $60 plans, and unused data expires after 30 days.

As great as the new Sprint Prepaid offering sounds, it does come with a catch...or two. For starters, the deal is exclusive to Best Buy, which means that you'll have to buy the service through the electronics retailer if you plan to accrue unused data. Additionally, Sprint says this is a "limited time" offer, which suggests it could disappear without warning.

In addition to introducing this plan, Sprint also launched a new live TV service, for Boost Mobile, another of its prepaid brands. Called BoostTV, it's a $10 monthly add-on that lets subscribers watch live and on-demand sports content.

The sports package delivers media from AyM Sports, Azteca America, BeIN Sports, BeIN Sports en Español, Fightbox, Latin American Sports and TyC.

Worth noting, the BoostTV service is only available on select smartphones: Samsung Galaxy S5 and S6 , Motorola E 4G LTE , HTC Desire , LG Tribute and Samsung Galaxy Prevail LTE . Sprint says it'll expand BoostTV to more phones in the future.