I believe the differences between public relations and marketing are mere nuances. Explicitly, I believe that public relations and marketing are different methods that share the same goal. Several years ago, during my undergraduate work in the buisness college, I was taught the standard definitions of marketing and public relations. Marketing was defined as "the process of planning and executing the conception, pricing, promotion, and distribution of ideas, goods, and services to create exchanges that satisfy individual and organizational goals." Public relations then, was the strategic management function that adds value to an organization by helping it to manage its reputation. Further, my defintion of the two concepts would have been that marketing efforts are paid forms of communication whereas public relations communications are free. However, by the time I was enrolled in graduate marketing classes, the internet had begun to change those standard definitions. Further, as viral marketing efforts increase,the lines between the two fields have blurred. Viral marketing efforts, while occasionally are the product of paid communications, often times result in free publicity. Some of the most popular examples include: Burger King's Subservient Chicken, Smirnoff Tea Partay and Green Tea Partay, and Folgers Coffee.
Integrated Marketing Communications is the advocation for all marketing messages to be integrated so that they tell the same story in the same manner to their target markets. Additionally, marketing communications can be integrated horizontally and vertically. Horizontal integration refers to consistent communications across the mix and the functions. Vertical integration refers to when marketing and communications objectives support the higher level corporate mission.
Therefore, as the marketers continue to integrate all communications across the board I believe the gap between public relations and marketing will continue to narrow. Interestingly, many companies include the public relations function within their marketing department.