Napster has announced it will enter the MP3 download market on Tuesday. The company hopes to lure customers away from iTunes, Apple’s online music store which accounts for 70 percent of the music downloads in the US, and Amazon.

Unlike iTunes, which mostly sells tracks in a format that plays only on iPods, Napster will come with mp3 tracks that can be played on any device. This became possible because music labels, seeing a drop in CD sales and fearing iTunes could become some sort of monopoly on the digital music download market, have agreed to allow companies to sell unrestricted digital music tracks and albums.

While Amazon already sells music without copy protection, Napster hopes it will have a greater success because its title library of about 6 million tracks is larger than Amazon’s, and Napster is a better known name when it comes to online digital music.

Until now, Napster has offered music only by streaming it over the internet to its subscribers, which, after paying a fee could listen to an unlimited number of tracks from the company’s database. One of the reasons Napster wanted to become an online store was to allow people to purchase the music they listened to.

The future could not be as bright as the company thinks. While beating Amazon sales is only a question of which company has a better understanding of the market, competing with Apple’s iTunes is a different matter. Even though ITunes sells music that can be played only on iPods, these devices are the most popular ones in the US, and users could see no reason to purchase music from anywhere else.