{blackbabes} Rihanna still atop Social 50 chart

NEW YORK (Billboard) – Rihanna holds at No. 1 for a third non-consecutive week on the Social 50 chart, which ranks the most active artists on the world's leading social networking sites -- MySpace, YouTube, Facebook, Twitter and iLike.

The ranking uses a formula blending weekly additions of friends/fans/followers along with weekly artist page views and weekly song plays. The final ranking also includes a measurement that identifies the ratio of page views to fans.

Justin Bieber bumps up 3-2, his third week in the runner-up slot in the five weeks that the chart has been in existence.

Lady Gaga rebounds 6-3 to reach a new peak, the Black Eyed Peas and Eminem stand still, holding at number 4 and 5, respectively. Akon ascends 7-6.

Leave it to a racy video to turn on the social masses. Enrique Iglesias' not-safe-for-work clip for "Tonight I'm F*****' You" premiered last week online and set the viral world on fire. The singer vaults from No. 21 to No. 7 with the largest gain of Facebook fans (up 125%) on the chart following the debut of "Tonight's" sexually charged video on December 23.

Rounding out the top 10 are Michael Jackson, who moves up a slot to No. 8, Linkin Park, which climbs 10-9, and Katy Perry, who drops 8-10.

Bay Area duo Pomplamoose has been inescapable this holiday season as they and their music have been the centerpiece of Hyundai's Christmas widely-seen television advertising campaign.

In the three spots, the act puts their distinctive spin on holiday standards "Jingle Bells," "Deck the Halls" and "Up on the Housetop." With that exposure, Pomplamoose is the top debut at No. 29 and posts the chart's best percentage gain among YouTube channel page views (up 78%).

With the absence of Pomplamoose holiday tracks at digital retailers, YouTube is a main source for those desiring to see the TV spots.

Keri Hilson also enters the tally at number 35, owed to the buzz generated by the release of her new album, "No Boys Allowed," on December 21. She posts percentage increases in all monitored social segments: Facebook, Twitter, YouTube, iLike and MySpace.