Until now, iTunes has been the only decent online music store. It made getting music as simple as possible, and their extensive library ensured that, unless you were looking for something really obscure, you could be sure to find the music you wanted. And since Apple made both iTunes and the popular iPod, they worked very well together.

Other stores have tried to compete, but they were dismal failures by comparison. On the one hand, you had stores like eMusic, which required a monthly subscription fee to download 50 MP3′s a month from their catalog of mostly independent musicians. On the other hand, you had stores like URGE or the Zune music store, which had extensive collections of popular music, but which crippled their music with DRM (software that locks music to a few particular players to prevent piracy), which made them incompatible with the iPod.

Finally, yesterday, Amazon combined the best of both worlds. They have an extensive collection of popular music, with everyone from Eminem to Luciano Pavarotti, from major labels like Universal Music, available as MP3 files without DRM. They can work on any MP3 player, including the iPod.

The other major advantage that iTunes had over its competitors was ease-of-use. In iTunes, all you have to do to get a song into your library is push the “purchase” button. It’s exactly the same for the Amazon MP3 store.

When you first start using the Amazon MP3 store, you have to install a tiny little client that will download your music and then put it into iTunes or Windows Media Player (whichever you prefer). After that, it’s just as easy as push the One-Click button next to a song or album. Amazon does have one extra step, where you confirm which credit card to charge with your purchase, but other than that, it’s just as seamless as using the iTunes store.

In fact, I’m willing to say that Amazon is better than iTunes in a lot of ways. First, you’re getting the songs in MP3 format, which means that you aren’t locked into using the iPod like you are with iTunes.

Second, you can browse for your music in your browser, rather than being forced to use the iTunes client. I’ve found that there are times when I want to go look through iTunes, but it’s ridiculously slow or plagued with network timeouts. I’ve never had that problem with Amazon’s website.

Third, Amazon tracks are often cheaper than iTunes tracks. Many songs in Amazon are only $.89, including popular songs on the top of their charts. iTunes tracks are always $.99, regardless of song popularity, and $1.29 for songs without DRM.

Overall, I’d have to say that Amazon is the first online music store that gives Apple a run for its money. I know that I’m planning to check Amazon before I check iTunes for my future music purchases.