AT&T Inc. is the largest telephone provider in the United States.
It also provides broadband and television services.
AT&T is the second largest provider of mobile telephony service in the United States,
with over 85.1 million wireless customers,
and more than 210 million total customers.
Even though AT&T is not the US' largest mobile telephone provider I believe it has a very strong competitive advantage in that area...
AT&T are the only ones who can sell IPhones.
& that is more than enough to make them stand out and place them above their competitors.
I do think that most people have "brand Loyalty" when it comes to cel phone providers.
My family was pretty much a Verizon family and I was somewhat "loyal" to Verizon...
Until the Iphone 4 came out.
Brand Loyalty towards cel phone providers is far less as strong
as brand loyalty towards other types of things..
If one cell phone provider (AT&T) is able to give you the phone of all phones...
You aren't going to care how long your family has been using a different provider(Verizon)..
You are going to do what you need to do to get that phone!
AT&T is an extremely successful company
and being the only ones able to offer customers the IPhone is definitely
one of the biggest competitive advantages I know of.