T-Mobile is gunning directly for Boost Mobile customers with two new promotions from MetroPCS.

The carrier's prepaid brand is offering $60 off any smartphone to customers who port their numbers from other carriers, enabling users who switch to receive one of nine smartphones free, paying just the sales tax. And MetroPCS users can now add a line to their family plans for just $25 a month, allowing them to access an additional 5 GB of data monthly when they already have a plan with the same or more data.

MetroPCS offers unlimited talk, text and 6 GB of LTE data each for two lines for $60 a month. T-Mobile is once again targeting customers with Sprint's Boost Mobile, which offers unlimited talk, text and 2 GB of LTE data for $35 per month on a single line. Boost accounts with two lines are as cheap as $65 a month, and three lines are as little as $90 per month.

"Trust me when I say we are seeing a lot of Sprint customers come on over to MetroPCS," T-Mobile CEO John Legere wrote on the carrier's website. "These guys should just tap out already. Because more people than ever are gonna be hearing about MetroPCS this week."

Major U.S. carriers once all but ignored the prepaid market, opting instead to focus on more lucrative postpaid smartphone users. But operators are increasingly chasing prepaid users as the growth of smartphone sales slows, and as the gap between prepaid and postpaid ARPU narrows.

T-Mobile posted a record 807,000 net prepaid customers additions in the first quarter, marking an 11-fold year-over-year increase in branded prepaid net customer adds. And it said MetroPCS generates an ARPU of roughly $38 to $39.

Meanwhile, Sprint lost a net 264,000 prepaid users during the most recent quarter, down drastically from the 546,000 net additions it posted in the prior year and substantially worse than Evercore ISI's estimate of 100,000 net losses. Sprint hopes to regain its footing in that market, though, with a major overhaul of its Virgin Mobile Brand. The operator recently named Jim Hyde as president of the Sprint Prepaid Group, placing Dow Draper at the helm of Virgin Mobile.

Sprint hasn't disclosed details about its new strategy with Virgin, but promises to divulge more information in the coming months.

For more:

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