Yes. All talk shows are free. The popular ones are free too but there may be a wait list.They're free right?
I went to the Letterman show. It was cool. I had to request the tickets and was on a wait list but I got two for free.
I was on the street in NYC and these people were on a street corner asking if they were interested in free tickets. I don't remember the show but it was a smaller network talk show.