Today in 1999, Napster released its file sharing service, letting people swap music stored on their computers.  On April 3, 2008, the iTunes Store surpassed Wal-Mart as the biggest music retailer in the US. In 2010, US recording industry revenues were $6.4 from physical media (e.g., CDs), $6.7 from online (e.g., a la carte downloads), and $2.4 from mobile (e.g., ringtones, full-track downloads).