The cost of bandwidth on AT&T’s networks has not strictly followed the cost curve for computing or storage. Any access networking professional knows why: access networks are construction projects, bound by atoms as much as bits.
So AT&T believes there is room for improvement of about four orders of magnitude, in fact.
That is one reason why AT&T has been so aggressive about software defined networks. SDN is seen as one key tool for driving out the cost of delivering bits over AT&T networks. And AT&T estimates the savings will have huge magnitude.