AT&T's prepaid service provider Cricket Wireless unveiled an unlimited talk, text and data plan for $70 a month, touting "a network that is bigger than T-Mobile's." Cricket also offers a $5 monthly "auto pay credit" for users who set up automatic payments, and the sum includes monthly taxes and fees.

Additionally, users who switch from T-Mobile will receive a $100 bill credit from Cricket. And while T-Mobile has aggressively expanded its nationwide LTE network over the last three years, Cricket maintains that it offers more coverage for less money.

"Cricket has over 275,000 more square miles of 4G LTE coverage than T-Mobile," President John Dwyer said in a prepared statement. "And our unlimited plan for a single smartphone line is $25 less a month."

AT&T limits download speeds for Cricket users to 8 Mbps on its LTE network and 4 Mbps on HSPA+ devices. Users who switch from T-Mobile will receive the $100 credit within 60 days of activation on Cricket's network, and an activation fee of "up to $25" applies.

AT&T's prepaid brand is taking direct aim at the nation's third-largest mobile network operator, which has gained tremendous ground by leveraging the buildout of its LTE network with a series of aggressive promotions and competitive service plans. T-Mobile is likely to be the only major U.S. carrier to report growth in postpaid net handset adds during the first quarter of 2016, Wells Fargo Securities analysts said earlier this week, enjoying a twelfth straight quarter of more than 1 million overall net adds.

Both T-Mobile and Sprint currently offer unlimited data options, though both have raised the cost of those plans during the past few months. For example, in November T-Mobile increased the monthly price of its unlimited data plans from $80 to $95.

AT&T, for its part, also offers unlimited data options, though that service is only available to customers of its DirecTV and U-verse services.

And, importantly, T-Mobile's own prepaid brand, MetroPCS, offers an unlimited data option for $60 a month.

AT&T's Cricket recently expanded its retail footprint in a big way with new distribution deals through Best Buy and the lease-to-own retail chain Aaron's. Like T-Mobile's MetroPCS, Cricket has gained substantial traction even as growth in the overall smartphone market in the U.S. slows to a crawl, taking prepaid market share from competitors such as Sprint's Virgin brand.

AT&T added 466,000 net prepaid subscribers in the third quarter of 2015, then scored another 469,000 in the fourth quarter thanks in part to a $63 million marketing campaign for Cricket. Analysts at Wells Fargo Securities recently predicted AT&T will report 250,000 net prepaid additions during the first quarter of 2016, up from 98,000 during the same period a year ago. AT&T is scheduled to report its first-quarter earnings April 27.

For more:

- see this Cricket press release

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