Perhaps in response to iTunes announcing it is the second music retailer in the U.S., Amazon has begun to release its download software on Ubuntu, Fedora, Debian, and OpenSUSE versions of Linux. This allows for an additional 1.34 percent of the personal computer market to purchase mp3 songs (1). Even though currently a small percentage, it is a percentage Apple cannot reach.
Download the Amazon MP3 Downloader for Linux here.
1. Source: ars technica