You can't say that the audience-centered concept used in this book was pioneered by them. After all, in the first paragraph the authors give credit to Aristotle for defining the elements of speechmaking as 'of speaker, subject and person addresed - it is the last one that determines the speaker's end and object.'
The first edition of this book, about 15 years ago, set the tone for what has now become the sixth edition, with each edition improved by audience feedback and new educational concepts. The general concept of keeping the audience at the center of of the speakers mind through all of the steps in the process.
Of course, this does not mean that the speaker tells the audience only what they want to hear; to do that would not convey anything to the audience but a good feeling. Some of the example speeches, 'I Have a Dream,' Martin Luther King, Jr., speak to people holding views very opposed to his.
The highly illustrated book is carefully organized with a mixture of text, tables, drawings, comments and questions to maintain the students interest while educating him. Indeed these techniques are some that can be used by the student in his speeches.