Rebecca Black Stays Strong on Social 50 Chart

Rebecca Black Performs 'Friday' Live on 'America's Got Talent'

Rebecca Black and her out-of-nowhere viral hit "Friday" continue to make waves on Billboard's charts this week. While Black herself slides 9-12 on the Social 50 tally -- the single rises 57-38 on the Digital Songs chart with 50,000 sold according to Nielsen SoundScan (up 35%).

The Social 50 ranks the most active artists on the world's leading social networking sites -- YouTube, Vevo, Facebook, Twitter, MySpace and iLike -- using a formula blending weekly additions of friends/fans/followers along with weekly artist page views and weekly song plays.

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Black's Social slide isn't unusual. Since the tally is based on weekly gains or declines in friends/fans/followers (and views), it's hard for an act to maintain full-throttle popularity for an extended amount of time. That makes Lady Gaga's hold of the No. 1 slot most impressive.

She spends her fifth non-consecutive week atop the list, with a strong gain in views to her YouTube and Vevo channels, thanks to the recent debut of the "country road" version of her single "Born This Way."

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As for the rest of the top 10, Justin Bieber, Rihanna, Eminem and Shakira all hold their respective slots at Nos. 2-5 while Katy Perry vaults 10-6 as her "E.T." single rises to No. 1 on the Billboard Hot 100 chart.

Akon is steady at No. 7, Chris Brown jumps 13-8 thanks to his "F.A.M.E." album release week activity, Lil Wayne motors 15-9 and the Black Eyed Peas zip 21-10.