Speaking at the Edinburgh Festival, Fincham compared the Simon Cowell talent show to Olympic long-distance runner Mo Farah, insisting that the missing viewers from last week's series nine launch were not worrying.
© ITV / Nicky Johnston
"It's not the 100m, it's the 10,000m. It's got years," said Fincham. "Think Mo Farah not Usain Bolt.
"It's an illusion to think that a show like The X Factor will go on a slide. People said that about Strictly after numbers fell for a couple of years and then it came back."
Last week's X Factor launch was the show's lowest since 2006.
When probed about the ratings drop, he added: "Oh gosh, X Factor is here for a long time.
"Last Saturday's X Factor was more than twice the size of the next biggest show on television.
"The figures were down, but it was the hottest weekend of the year and I think it's not unreasonable to say in the immediate aftermath of the Olympics viewing figures have gone down. People gorged themselves on TV in the Olympics.
"How long has The X Factor got implies that it does have a finite life. I don't agree with that proposition."
However, Fincham did express concern that the big entertainment shows "that dominated the last decade" such as I'm A Celebrity, The X Factor and Strictly were making it hard to create new series.
"It's difficult to grow similar brands on the same scale," he said.
The X Factor's second episode airs tonight (August 25) on ITV1.
Photo gallery - The X Factor Show 2:
Copyright: Thames TV
