AT&T's latest promotion: Get 15GB of data for price of 10GB

AT&T is the latest wireless carrier to provide more bang for the buck when it comes to data.

Starting Tuesday, the Dallas telecommunications provider will offer 15 gigabytes of shared data for $100, the price it previously charged for 10GB of data. The offer is a limited promotion, and AT&T didn't say when it would expire.

The promotion is just the latest offer by a wireless carrier going into the critical holiday shopping season. With smaller rivals Sprint and T-Mobile getting aggressive with their own offers, a larger company like AT&T is feeling the pressure to respond in an effort to defend its customer base. Rather than compete on price, the carriers have largely been offering more data instead.

The competition isn't cooling off. Sprint CEO Marcelo Claure last week teased even more aggressive moves in the coming weeks. T-Mobile Chief Financial Officer Braxton Carter said last week it was taking a majority of its market share away from AT&T and Verizon Wireless, the nation's two largest wireless carriers. Verizon, meanwhile, will likely also get into the promotional game in the coming weeks.

AT&T previously offered to double the data on its shared data plans, starting at the 15GB tier -- or 30GB under the promotion -- which starts at $130 a month. The latest promotion adds in an extra 5GB of data to the 10GB plan.

As with all of its plans, customers need to pay an additional access fee for their devices, which range from $15 when on a monthly installment plan or $40 when on a contract. A tablet costs $10 a month.

A family of four paying through its AT&T Next monthly installment program would pay $160 for 15GB of data, in addition to the fees related to their devices.

Customers who sign up for the promotion keep the extra data for as long as they keep their plan.