Product Life Cycle
When deciding upon your unique marketing communications mix, you should also consider the Product Life Cycle. Here are some general guideline as to how and when to emphasize different parts of the mix according to the stages of a typical product life cycle:

Introduction: Heavy use of advertising, public relations for awareness, sales promotion for trial
Growth: Advertising, public relations, branding and brand marketing, personal selling for distribution
Maturity: Advertising decreases, sales promotion, personal selling, reminder & persuasion
Decline: Advertising and public relations decrease, limited sales promotion, personal selling for distribution