'X Factor' Finalists Alex & Sierra Notch iTunes No. 1, Show Sales Potential

Thanks to covers of songs by A Great Big World, Sara Bareilles and Of Monsters and Men, the boyfriend-girlfriend duo are the buzz of season three.
Jeff Lipsky / FOX

Couple and singing duo Alex & Sierra have made a name for themselves as one of the final four contenders on season three of X Factor, proving a clear connection with the viewing audience despite floundering ratings. 

Indeed, it's the two's endearing love story and spot-on vocals that have delivered some of the show's strongest moments. Last week, their rendition of "Say Something" surpassed Christina Aguilera and A Great Big World's current radio hit by creeping up to No. 1 on the iTunes chart the morning after they sang it onstage. And as of Dec. 12, their cover of Sara Bareilles' "Gravity" had climbed to No. 2.

Series creator and head judge Simon Cowell, who mentored the groups, says Alex & Sierra's success is proof that the show is still capable of turning small-town kids into bankable stars. 

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"It's incredible," Cowell marveled. "I've always said this about these shows -- it's not about winning a silly trophy, it's about launching an artist. It's about a career outside of it and that's what I'm most proud of. It does launch proper artists. We have to trust our A&R abilities, that this show can find better artists that anyone else. That's the future of the show." 

While few can remember the actual winners of the U.S. version of the show, it has churned out a few still-building acts in its four season run. Season two's Emblem 3 and Fifth Harmony are gaining momentum, with the latter slated to open for judge Demi Lovato on her next tour. But both pale in comparison to X Factor U.K. grads One Direction, who may end up one of the biggest success stories of the decade.

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That's not to say that Alex & Sierra don't have competition. In fact, the bar was raised again on Wednesday night when finalist Jeff Gutt floored the panel and the country with a take on Leonard Cohen's "Hallelujah." His version of the song soared to the top spot on iTunes before the show stopped taping and solidified his place as a potential moneymaking artist as well. 

But despite Gutt's strong showing, the judges still think Alex & Sierra will take home the win this season, and Cowell compared their shining moments to some of the biggest stars the show has ever produced. 

"You always have a moment ... [with] certain contestants. I can remember having it with One Direction and Leona Lewis," he recalled. "There's one song where you go, 'I can see this working.'"

Lovato agrees that the couple could be the last ones standing. "I think Alex & Sierra are going to take it," she said. "They are so talented, it's insane. Even if they don't win, they are going to succeed."