First of all, let me state that the term 'graphic designer' has been thrown around to the point where it has minimal professional credibility. As for my title, I prefer Graphic Communicator since my primary responsibility is to provide the viewer with well-organized and easily digestible information.
Think in terms of today's viewer/reader; they are skimming copy, interpreting graphics and simultaneously veering away from intentionally disruptive material that is thrown in front of them while moving at 200 miles per hour. Please think in terms of a police car involved in a high-speed chase with a suspect. In between the two vehicles is a pick-up truck with passengers rolling 50-gallon drums of paint off the tailgate and in front of the police cruiser.
The materials that I designed to accompany David Meerman Scott's online course, 'New Marketing Mastery,' is an excellent example of non-disruptive communications. The gridded and informationally-leveled layouts allow the reader to ingest information without disruption easily.
My job as a Graphic Communicator is to lead the viewer from Point A. to Point B. with as little chaos as possible. Providing this clear pathway is accomplished through well-organized pages (whether on a screen or paper), leveled copy (headline, sub-head, body copy) and infographics designed to interpret the information included in the text visually.
To answer the question above, almost any business except for street corner or stadium vendors and hawkers ("Get your cold beer here!"), requires the assistance of a professional Graphic Communicator. –Doug.