AT&T announced during the weekend that it is doubling the amount of data users get with its Mobile Share Value plans. This means that the company's current 15, 20, 30, 40, and 50GB plans have now been doubled to 30, 40, 60, 80, and 100GB, respectively, at no additional charge. The promotion applies to new and existing customers as long as you sign up by October 31. 

So for $130 per month, the carrier is now offering 30GB of shared data instead of 15GB. Similarly, for $150, $225, $300, and $375 per month, you'll now get 40GB, 60GB, 80GB, and 100GB, respectively. The 10GB Mobile Share Value plan is not eligible for the promotion.

"With these new double data plans, and smartphones for $0 down with AT&T Next, there’s never been a more affordable time to be with AT&T", the company's Mobility chief marketing officer David Christopher said in a statement. The promotion runs till October 31st, and is available to both new and existing users.

It's worth mentioning that you can keep your new promotional shared data amount as long as you want, as there is no expiration. However, if you need to change your plan after the promotional period ends, you will need to select from the previous Mobile Share Value offers.

AT&T's Mobile Share plans offer unlimited text, talk, and international messaging, while providing a pool of data that can be used across multiple devices, although there are extra charges, ranging from $15-$40 per month, for each device you add. However, at this time new customers or those who activate a new line of service with a smartphone on AT&T Next will receive a $100 bill credit.