"In recent years, cellular (mobile) service providers have worked hard to eliminate "dead zones," providing customers with service wherever they travel. By working to make the network available in more locations, cellular service companies are focusing on __________ value creation."

In reference to marketing, Value can be defined as the preference which a customer shows towards one commodity, say A, after analysing and comparing the cost to benefit ratio of the commodity A when compared to another commodity, say B.
The customer tends to choose commodity A over commodity B only when he gets better benefit from the commodity A as compared to commodity B.
Value can be divided into four categories:

Functional Value: Here the customer benefits from the purchase of a commodity as the commodity provides a solution to the customer's need.
Monetary Value: Here the customer chooses to buy a commodity after getting attracted to the cheaper price at which the commodity is available. This commodity may or may not be beneficial to the customer.
Social Value: Here the customer chooses to buy a commodity that allows the customer to connect or link with others.
Psychological value: Here the customer buys a commodity that appeals to his senses and makes him feel good.

In the given question, as the elimination of "dead zones" in mobile networking area improves the connectivity among people, so this is an example of Social Value.