A recent Walrus Magazine article reviews a number of books that discuss the state of advertising and whether or not PR is controlling the news.
You can't blame Al Ries or Judy Lewis or others in the PR industry for taking what the media offer them. If they can convince enough editors, hosts, producers, or reporters that the launch of a new flavoured soft drink or the arrival of a new donut or grocery chain is "news," why should they fork out the money to buy advertising? So what if various media outlets choose to deprive themselves of precious ad revenue by surrendering some of their valuable editorial space to free publicity?
The article has some interesting points, and predicts that the rise of PR will mean not only the fall of advertising, but the fall of journalism as well.