Justin Bieber Retakes Social 50 Chart Crown; Jessie J, Radiohead Debut
Justin Bieber Retakes Social 50 Chart Crown; Jessie J, Radiohead Debut

U.K. pop sensation Jessie J (above) debuts along with Radiohead on this week's Social 50

Lady Gaga may retain the throne on the Billboard Hot 100 singles chart with "Born This Way," but she slips from the top slot on the Social 50 tally, down to No. 2. Who's she replaced by? Why, the act with the No. 1 album in the country -- Justin Bieber.

The Biebs jumps 3-1 in the wake of social buzz generated by his Grammy Awards performance on Feb. 13, the continuing success of his documentary film "Never Say Never" and its album of the same name. The latter opened at No. 1 on the Billboard 200 this week with 165,000 copies sold according to Nielsen SoundScan.

The Social 50 ranks the most active artists on the world's leading social networking sites -- YouTube, 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.

Nicki Minaj stirs up excitement on the chart too, as she rallies 15-4 -- though Lil Kim (who has been keeping herself in the news lately thanks to her feud with Minaj) is no where to be found on the list. The Black Eyed Peas' climb back up the list 19-8 while Ludacris also jumps back into the top 10, moving 21-9.

Rihanna falls 2-3, Eminem, Akon and Katy Perry holds at Nos. 5, 6 and 7, respectively. Rounding out the top 10 is Linkin Park, who falls one slot to No. 10.

Drake re-enters at No. 20 following his Grammy performance with Rihanna, while Radiohead debuts right behind him at No. 21. Certainly the latter's entry is enabled by the chatter garnered by the release of its new album

"The King Of Limbs," which went on sale Feb. 18. The act saw a 40% week-over-week gain in Facebook fans, a 555% jump in Twitter followers and a 657% leap in YouTube channel views. ("King" does not appear on Billboard's charts this week, as its sales were not reported to Nielsen SoundScan.)

Also returning to the list this week is Bruno Mars at No. 46, who is closely trailed by the debuting new British singer Jessie J, bowing at No. 47. She's currently enjoying the success of her first U.S. hit single, "Price Tag" (featuring B.o.B) which climbs one rung to No. 99 on the Billboard Hot 100 this week.