Sirius XM Radio Inc. broadcasts its music, sports, entertainment, comedy, talk, news, traffic and weather channels in the United States on a subscription fee basis through its two satellite radio systems. Subscribers can also receive certain of its music and other channels over the Internet, including through applications for mobile devices. As of December 31, 2011, it had 21,892,824 subscribers. Its subscribers include subscribers under its regular and discounted pricing plans; subscribers that have prepaid, including payments made or due from automakers for subscriptions included in the sale or lease price of a vehicle; radios activated for daily rental fleet programs, and subscribers to its Internet services who do not also have satellite radio subscriptions. In January 2013, Liberty Media Corporation announced it held 50.7% interest of the Company.