Amaro won the chance to appear in the soft drinks giant's commercial when she triumphed on the first season finale of The X Factor in December.
The teenager, who was mentored by Simon Cowell, also took home a $5 million recording contract, later signing to Epic Records.
Speaking to Entertainment Weekly about the commercial, she said: "I'm a singing princess warrior [and] I have to try to get the entire kingdom some of the sacred treasure, and the sacred treasure is, of course, Pepsi.
"I have to go through the talent part of the being in front of the king at his court [to get the treasure], and my talent was, of course, to sing. So I sing, I blow his mind, and I get everybody to have some of the Pepsi."
John will play the king in the commercial.
He told Good Morning America this week: "I always think it's hard being a talent show winner. It's too much fame at once. There will be a constant barrage of interviews, press photographs, publicity photographs.
"I used to love that but I also had the experience to back it up with and that's vital. I think to be thrust into the limelight on television you then have to learn your trade on stage. We did it the other way around."
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Amaro previously said that she was excited to be following in the footsteps of previous Pepsi Super Bowl commercial stars, saying: "So many big people like Mariah and Britney did it, Beyoncé did it... and then after them will be 'Melanie Amaro did it'.
"I feel blessed and so grateful to be in a commercial, especially for Pepsi, and I feel that I'm following in the footsteps of those great divas."
Fellow X Factor contestant Stacy Francis recently tweeted to followers that she had seen Amaro's commercial and promised fans that they wouldn't be disappointed.
In a message to Amaro, she said: "Saw your commericial!! HOT HOT HOT!! CONGRATS!!!... the world is going to gag... can't wait for the world to see u! xox (sic)"
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