American Idol, the reality singing competition that inspired dozens of spinoffs with its success, experienced its biggest ratings drop during the premiere of its 11th season Wednesday night.

The kickoff episode about auditions in Georgia sank 27 percent in viewers from last year's season premiere among adults 18-49 years old, making it the biggest season-to-season drop in its history, according to Billboard.com. The premiere attracted 21.6 million viewers total. At its peak in 2007, Idol was watched by 37.4 million people.

Fox still won the ratings game overall, nearly doubling the viewer average for CBS.

Will ratings continue to fall? Here are other signs that the show is approaching its expiration date:

Too many spinoffs. The X Factor, The Voice, America's Got Talent... how many shows of the same genre can a reality junkie keep track of? Idol may have been the original, but it doesn't matter if other shows are just as well done, if not better. Idol may have lost much of its audience to those shows.

Winners are losing star power. Most people have heard of Kelly Clarkson. Over her decade-long career, she's enjoyed the most success of all the Idol contestants and has written hits like A Moment Like This, Because of You and My Life Would Suck Without You. How many people are familiar with Ruben Studdard's music? Or David Cook's? Didn't some girl named Fantasia boycott the Grammy's or something? With the exception of Carrie Underwood, who has hosted the Country Music Awards and won several Grammys, most American Idol winners do not skyrocket to fame after the season ends.

Same old plotlines. In Wednesday night's episode, there was a  completely untalented but endearing singer named Mawuena Kodgo who sincerely believed he was destined for stardom; 20-year-old Phillip Phillips, who hoped to take his guitar from café gigs to the big stage, got rave reviews from the judges; judge Steven Tyler made a contestant's father uncomfortable by telling him his 15-year-old daughter was hot, humid and happening. As hilarious as the former Aerosmith frontman is, all these plotlines have been done before. Idol execs have certainly shaken things up with the departure of Simon Cowell and the addition of Tyler and Jennifer Lopez as judges over the years, there's nothing particularly new about this upcoming 11th season.

And here's one really big sign that it's not going anywhere soon:

It's still No. 1. Even considering all of the above, American Idol still dominated the ratings. It may have been getting old, but there's certainly a reason why people still tune in year after year, and why so many other shows have mimicked it. It's a reality TV classic.