Pandora has reached 200 million registered users in the U.S.
Pandora founder Tim Westergren said. "It is now clear that radio is changing, and that's great news for music fans and for the tens of thousands of working artists who now have a home on the air."
Pandora was founded in 2005 and reached 100 million registered users in July 2011 to double it less than 2 years later.
Despite the success recorded, Last month, Pandora reported its fiscal fourth-quarter loss widened as a rise in the Internet-radio provider's expenses outpaced its revenue growth.
Should Pandora exclude free services?