Vázquez Sounds’ popularity seems to be growing in the United States…

The Mexican siblings—who’ve become YouTube sensations for their impressive covers of Adele’s “Rolling in the Deep” and Mariah Carey’s “All I Want for Christmas”—have landed on No. 17 on Billboard’s Social 50 chart.

It marks the second-highest debut ever on the chart since it launched a year ago. Only Rebecca Black, who rose to fame with the music video for her single “Friday,” bowed higher – at No. 9.

The chart’s rankings are determined by activity monitored on YouTube, Vevo, Facebook, Twitter, MySpace and iLike, using a formula that blends weekly additions of friends/fans/followers along with weekly artist page views and weekly song plays.

Vázquez Sounds, comprising of 10-year-old Angie, 13-year-old Gustavo and 15-year-old Abelardo, has already signed a recording contract with Sony Music Mexico and have made their covers already available for download on iTunes.

The trio’s “Rolling in the Deep” clip has racked up more than 18 million views since the siblings posted it online on November 10, while the group’s cover of Carey’s Christmas song has notched 7 million views. And, Vázquez Sounds currently has the top two selling songs in the iTunes Mexico Store