MP3 download web sites allow music lovers to access and purchase a large variety of songs and music videos online. Most of the early websites offering MP3 downloads were illegal. However, after years of dominance by illegal sites and by peer to peer sharing applications that made swapping MP3 files easy, legal download services are rapidly becoming popular. With a large number of legal download sites emerging, it has become difficult to find out where to get the best deals and which sites to trust.

Some of the most popular MP3 download services include WinMX, iTunes, LimeWire, Kazaa, BearShare, Ares Galaxy, Napster, Morpheus, Real Player Store, iMesh, MSN music, Yahoo music and even Walmart.

MP3 download sites generally charge their customers either a fixed price for each music file that is downloaded or a monthly subscription fee and a charge for music downloaded. In case a monthly fee is charged, the cost for each track downloaded is generally lower than those sites which do not charge a subscription fee. Often the latest music tracks are priced more than tracks that have been released earlier. To encourage music lovers to buy music tracks in larger quantities, some online music stores offer progressive pricing which allow users to buy tracks at a cheaper rate if they increase the quantity of music tracks they purchase. The number of songs on these online stores range from about half a million on emusic to over a million and a half on itunes.

Online music stores also provide music reviews, allow users to request music and also offer gift certificates for purchase. To encourage trials, sites such as emusic provide 25 or even 50 MP3 music files free and charge as low as 25 cents per track after the trial period is over. Indulging in comparison shopping to find out which MP3 site is offering the greatest deal would be the best thing to do.