The function of all elements of the IMC program is to communicate, so promotional planners must understand the communication process. This process can be very complex; successful marketing communications depend on a number of factors, including the nature of the message, the audience's interpretation of it, and the environment in which it is received. For effective communication to occur, the sender must encode a message in such a way that it will be decoded by the receiver in the intended manner. Feedback from the receiver helps the sender determine whether proper decoding has occurred or whether noise has interfered with the communication process.

Promotional planning begins with the receiver or target audience, as marketers must understand how the audience is likely to respond to various sources of communication or types of messages. For promotional planning, the receiver can be analyzed with respect to both its composition (i.e., individual, group, or mass audiences) and the response process it goes through. A number of models of the response process have been developed including the AIDA, hierarchy of effects, innovation adoption, and information processing model. Different orderings of the traditional response hierarchy include the standard learning, dissonance/attribution, and low-involvement models.

The cognitive response approach examines the thoughts evoked by a message and how they shape the receiver's ultimate acceptance or rejection of the communication. The elaboration likelihood model of attitude formation and change recognizes two forms of message processing, the central and peripheral routes to persuasion, which are a function of the receiver's motivation and ability to process a message. There are three critical intermediate effects between advertising and purchase including cognition, affect, and experience. Those responsible for planning the IMC program should learn as much as possible about their target audience and how it may respond to advertising and other forms of marketing communications.