What the organization wants to achieve determines the priority publics.But in public relations, anything can be used as a channel for communications--door-knob hangers, mayors' or governors' proclamations, open houses, marathon races, parades and so on--the list is almost endless.The most effective programs encapsulate the individuals composing the target publics in carefully selected messages delivered through channels that are highly believable and credible to the individual public.The public relations writer is a vital part of the total success of a campaign because it is the writer, more than anyone, who interprets the objectives, goals and strategies to relevant publics.If the latter is more important--the case with introducing new ideas, services or products-- then the campaign is primarily an advertising campaign with publicity and special event sup- port.A public relations writer usually is directly involved only in helping to review or craft mes- sage strategies and in the implementation phase.Once the publics are identified, the media to reach them are clear, or should be. Thus a campaign might be designed that involves no mass media at all, either for publicity or for advertising.On the other hand, the primary publics might best be reached through the mass media, and the mass media they hold credible may be needed for one or both of two public relations purposes.The second is advertising to give guaranteed exposure in tar-geted media.One is employing publicity to give third-party credibility to other messages origi-nating from the organization.When a campaign is primarily directed to specialized audiences, there may be little or no use of mass media.Some ads may be bought in trade or professional journals supported with publicity in the same media.Certainly not.