Services are economic activities offered by one party to another, most commonly employing time-based performances to bring about desired results in recipients themselves or in objects or other assets for which purchasers have responsibility.
In exchange for their money, time and effort, service customers expect to obtain value from access goods, labor, professional skills, facilities, networks and systems; but they do not normally take ownership of any of the physical elements involved.
Services Marketing by C. Lovelock and J. Wirtz
Hospitality for PBL 