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.
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."
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.