AT&T seems to be very intent on one-upping its competitors in the rate plan equipment financing race, and most recently, the data rollover race. Its clear that AT&T is well aware of T-Mobile's momentum, and wants to make sure it is prepared to keep its customers where they are.
Its most recent introduction is a new limited time offer on a Mobile Share Value Plan, which it slots between its 6GB for $70 and 10GB for $100. For $75 per month you can now get 7GB of data, and the per-line charge has been further discounted to $15 per-line on AT&T Next or no contract devices.
Additionally, AT&T will give $100 bill credit to new customers who switch to AT&T and buy a smartphone on AT&T Next. Additionally the offer is also eligible for AT&T's Rollover Data, which allows you to transfer your unused data to the following month.
This means, two devices with no contract or AT&T Next on the new 7GB plan, the monthly cost is $105, versus $120 per-month on the 6GB plan with the same set-up. So its clear that the 7GB plan is a great option, and worth considering over the current 6GB plan. The plan will be available beginning February 15th, but you better act soon if you dont want to miss out.
source - AT&T