AT&T will offer Mobile Share Plan users free access to Apple’s FaceTime service at no extra charge, but will not extend that to other users on its service, reports MacRumors. Whether AT&T would charge for the feature had become a topic for discussion since Apple revealed that iOS 6 users would be able to use it over cellular networks as well as WiFi.

AT&T calls it an ‘added benefit’ of signing up for a Mobile Share plan:

AT&T will offer FaceTime over Cellular as an added benefit of our new Mobile Share data plans, which were created to meet customers’ growing data needs at a great value. With Mobile Share, the more data you use, the more you save. FaceTime will continue to be available over Wi-Fi for all our customers.

The new sharing plans were announced last month and will arrive on August 23rd. The plans won’t automatically save money for most users. If you have an unlimited talk and text plan then you might find a way to end up with a cheaper bill if you juggle them. If you’re not a heavy SMS or talk user, they’re likely to raise your bill, rather than lower it.

Screen Shot 2012 07 18 at 12.11.411 AT&T to provide free FaceTime service over cellular for data sharing plan users only

Offering FaceTime over 3G and 4G to those users only is kind of sucky, frankly. Sprint has already said it won’t charge for the feature and Verizon has yet to clarify. Verizon also recently announced shared data plans.