Songs are encoded by Dolby's Advanced Audio Codec, which is part of the MPEG-4 standard and QuickTime 6 and is usually considered superior to MP3 in terms of 128 kbit/s encoding quality.
Originally only Mac OS X users who had credit cards with a U.S. billing address could buy songs with the service, but Steve Jobs, the CEO of Apple, announced plans to support both Windows and international users. The Windows version of iTunes, and support for the Windows platform from the iTunes Music Store was announced on October 16th, 2003, with immediate availability.
The iTunes Music Store was the first of now many online music stores, opening up the path for many other services to join the so-called "revolution."
Fans and some executives in the music industry say that the Music Store has more attractive characterstics than previous services such as Rhapsody and MusicNet: it allows the user to legally purchase an unlimited number of songs and transfer them to the iPod, and is comparatively simple and easy to use because it is closely integrated into the iPod and iTunes product lines. Currently, the iPod is the only digital music player that works with the iTunes Music Store (however other players work with iTunes), and iTunes Music Store is the only music store available for iPod users.
Apple's FairPlay Digital rights management (DRM) is integrated into iTunes, which manages songs purchased from iTunes Music Store. To convert protected files to MP3-format files, the user must burn them on an audio CD and then rip the CD back to iTunes using the MP3 encoder, resulting in slight loss of quality.
The store sold about 275,000 tracks in its first 18 hours and more than 1,000,000 tracks in its first week. When released for Windows, it was downloaded more than 1,000,000 times in the first 3 days and more than 1,000,000 songs were sold in that period. On 15 December, Apple announced that it had sold 25 million songs since the launch in April. In January 2004 at the Macworld Conference & Expo in San Francisco, Steve Jobs announced (as cited in Sellers, 2004) that an unnamed person had purchased 29,500 USD worth of music.
Currently, new songs are added each Tuesday, and beginning with Moby on July 29, 2003, independent artists are now included.
On February 1st, 2004, Apple plans to launch a promotion with Pepsi in which they will offer to give away 100 million songs, through tokens on selected soft drink bottle caps. This might have contributed to Coca-Cola's (sometimes considered out of character) decision to launch a music store as well.
On January 8th, 2004, Apple and Hewlett-Packard announced a strategic alliance to deliver an HP-branded digital music player based on Apple’s iPod, and Apple’s iTunes digital music jukebox and online music store to HP's customers.