Prior to American Idol, Mercado was on The One: Making a Music Star and she won Florida Super Singer.

Her musical influences are Whitney Houston, Etta James, Alicia Keys, Zap Mama, Lauryn Hill, and Aretha Franklin.

[1] Mercado played Deena Jones in the United States national tour of Dreamgirls that also opened internationally in Japan.

[4] Her mother, Zelda, a former Motown backup singer, is African American and her father, José, is of Puerto Rican descent.

[8] Dreaming of becoming a gospel singer one day, Mercado signed a contract at age nine with the Take Stock in Children, a scholarship program for "low-income families who show potential for college, but are unlikely to be able to afford a higher education.

"[11] She auditioned for the seventh season of American Idol in Miami, Florida, singing "Think" by Aretha Franklin where she made it to Hollywood with all three judges saying 'yes'.

This meant a tie with first season fellow 3rd place finalist, Nikki McKibbin, for the most weeks spent in the bottom three or two at the time.

Some commentators, including American Idol judge Simon Cowell, believed her style was more suited for Broadway than pop music.

[15] After her elimination, Mercado appeared on Live with Regis and Kelly, The Morning Show with Mike and Juliet and WSVN's Deco Drive.

She was the guest host of the WSVN 7 yacht at the 37th annual Seminole Hard Rock Winterfest Boat parade on December 13, 2008.

[citation needed] It was officially confirmed on June 25, 2009, that Mercado landed the lead role of Deena Jones in the upcoming United States national tour of Dreamgirls.