The exact message reads: "You now have FREE calling to any U.S. mobile phone. We've upgraded your messaging plan to Messaging Unlimited with Mobile to Any Mobile Calling at NO additional cost to you. Just our way of saying thank you for being an AT&T customer."
Judging from the photo, our tipster is an Apple iPhone user and with the increased competition from Sprint and Verizon, it seems that AT&T really, really wants to keep iPhone users on board. Showering customers with free upgrades and rollover minutes is one way to do it, but if Sprint keeps its unlimited plans for iPhone 5 users as we told you they plan to do, it might be hard for AT&T to prevent some of its iPhone users from walking once their contract expires. After all, Sprint doesn't throttle data speeds or charge overage rates on customers.
If you also received this free upgrade, you can let us know by dropping a comment in the box below!