The signature of the show has been the outlandish audition phase. That was the gimmick and great marketing from the beginning to get people watching. There are many phases people have to go though just to get to the judges, but of course for TV purposes even the non-singers got through.
Throughout the course of the show viewers were taken on a journey from the audition phase to Hollywood to the main stage where they would be narrowed down, via fan voting, from the final 16.
There have been a lot of alterations in the show since it’s beginnings such as change in format by adding a Vegas round, change in age (18-28 since season 4), and most noticeably the change in judges. Paul Abdul left at the conclusion of season 7 and was replaced by Kara DioGuardi until her departure after season 9. DioGuardi was then replaced by Ellen DeGeneres and then another main drop in the original judge panel with Simon Cowell’s departure.
The downfall of American Idol happened right around the time Paula Abdul left. There was nothing new about the show, people really didn’t watch past the auditions, and it looked like Simon, especially, was bored. He left and went on to launch the U.S. Version of the UK show, X Factor.
The initial concept and production if the show was great, but now it seems boring. I do not think that people outside of the music business should have ever been judges. I know it’s a different perspective, but how can you really judge if you’re not in music. I feel Ellen DeGeneres only lasted a season based on that.
Record sales wise, the album sales have slot descended since Taylor Hicks of season 6. I guess it all depends on the genre you’re going into.