Talk Shows and American Culture

What do Jay Leno, David Letterman, and Oprah Winfrey have in common? They are the hosts of the most popular talk shows. I mostly watch David Letterman’s late show on CBS. There is a certain type of pattern in the show, and many other show hosts such as Craig Kilborn and Conan O'Brien are sharing this pattern. Although the Nielsen Media Research shows that the rating for such talk shows is not as high as other TV shows like Friends nowadays, I still want to make an in-depth analysis of talks shows because there is no such talk shows in the country I came from; therefore I think they represent the American culture in a certain way.
The requirements to be a talk show host are the ability of giving a good speech and sense of humor. David Letterman has them both. Hosts need these qualities to conduct the show, to bring enthusiasm and excitement. Can you imagine what would happen if a host has nothing else to say five minutes after the beginning of the show? Dave never has this k...