Well, UCD can improve the usability and usefullness of everythings from "Everyday things" to softwares to information systems to processes....anything with which people interact.
The characteristics of a design that is user centered is that due to that design easy-to-use products can be made,
it satisfies customers,
Decrease expenditure on technical support and training,
Advertise ease-of-use successes,
Ultimately increase market share.