"The X Factor" is a reality competition, launched by Simon in Britain in 2004 and it became so big – discovering the likes of Leona Lewis in its third season – that it replaced "Pop Idol," the British parent show of "American Idol."
While "The X Factor" and "American Idol" are both singing competitions, they differ when it comes to age, judging and tone.
"Idol" only takes contestants ages 16-28, while the more dramatic "The X Factor" has no upper age limit and focuses on the backstage drama.
"You can have, you know, someone in their 60's competing with someone in their teens," Simon explained in an interview on Monday with FOX. "There are literally no rules in this competition and what makes it more fun to be on is the fact that the judges mentor the contestants."
And unlike "Idol's" top 24, "The X Factor" whittles things down to 12 contestants before at home judging begins.
U.K. entertainment journalist Ashley Pearson said "X Factor" has the it-factor.
"The difference really is that 'X Factor' is a little bit nastier, a little bit snarkier and a little bit more evil than the other one," she told Access.
"With Simon as a mentor and a judge, that means more camera time and more Simon. But could that mean higher ratings? No one is more excited about the possiblity of that than FOX President of alternative programming Mike Darnell.
"I couldn't be personally more excited to have 'X Factor' coming to the network," he told Access on Monday. "And so [Simon's] not leaving the network. Thank God!"
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