Call it wireless tit for tat. When T-Mobile makes a move, AT&T responds. But the nation’s second-largest wireless carrier is giving T-Mobile a January double-whammy with back-to-back pricing promotions it hopes will keep customers on its side.

Indeed, AT&T is giving consumers one more reason to stick with -- or sign on -- to its wireless service. Starting today, all new and existing AT&T customers will receive a $100 bill credit for each new smartphone, tablet, feature phone, mobile Relevant Products/Services hotspot or wireless home phone line of service they add to the network. The limited-time offer ends on March 31.

“Customers want the best of both worlds from their wireless carrier . . . great value on their plans and service on a phenomenal network and AT&T provides both,” said David Christopher, chief marketing officer for AT&T Mobility. “This $100 credit is a way we can reward our existing customers who add an additional line of service for their loyalty, and it’s an incentive for customers of Verizon, Sprint, T-Mobile and other wireless carriers to come to AT&T and enjoy the nation’s most reliable 4G LTE network.”

A Win-Win

We caught up with Jeff Kagan, a wireless industry analyst, to get his take on AT&T’s latest promotion. He told us he’s bullish on the new offer.

“This is a way for AT&T to work with customers on a loyalty program that benefits both. The customer Relevant Products/Services gets cash and AT&T creates an even more stable customer base,” he said. “This is a win-win for both the customer and for AT&T.”

In early January, AT&T started offering T-Mobile customers the opportunity to “upgrade their mobile lifestyle” with up to $450 per line when they switch to AT&T and trade in eligible smartphones.

AT&T is ticking off reasons why T-Mobile customers should take the company up on its offer. In addition to the $450 per line, AT&T pointed to its “larger and more reliable 4G network.” The company also promised switchers a superior smartphone lineup and award-winning customer service.

Wireless Wars Heat Up

The wireless wars have heated up this year. Also in January, Sprint launched the Framily Plan. The idea is to let consumers decide who they consider family. That may mean your favorite barista becomes your brother, your fantasy football team become your cousins, and the parents on your son’s soccer team become in-laws. Any group of family, friends and others can now be considered, as Sprint calls them, “framily.”

“The Sprint Framily Plan redefines the way we think of family plans and gives our customers the power to decide who will be a part of their group and gain greater savings as more members are added,” said Dan Hesse, Sprint CEO.

All this may be in response to T-Mobile’s New Year’s resolutions to transform the industry. T-Mobile CEO John Legere, known for his attention-getting marketing efforts, posted a Twitter photo that featured his resolution list for 2014, which includes continuing to remove customer pain points; faster and louder 4G LTE; unshackling the family from “those other guys”; making waves at the 2014 Consumer Electronics Show (CES), and “giving AT&T a break . . . or not.”