This edition marks the one-year anniversary of the launch of Billboard's Social 50 chart. While a number of star acts never left the tally (Justin Bieber, Lady Gaga and Rihanna), there have been many viral stars in 2011 with impressive peaks like Pomplamoose (No. 29), George Watsky (No. 13), Rebecca Black (No. 9), Karmin (No. 15) and Kina Grannis (No. 49) that deserve recognition.
