Amazon has got in first with an online music storage service, or "Cloud Drive" as the bookseller puts it.
Amazon's service gives you 5GB of free music storage which can then be played back on any Android phone, Mac, PC or even a tablet.
If 5GB is not enough then buy any MP3 album through Amazon and you get upgraded to 20GB. If you don't want to buy an album then you can pay $20 a year for the 20GB upgrade.
Bill Carr, vice president of Movies and Music at Amazon. "The launch... eliminates the need for constant software updates as well as the use of thumb drives and cables to move and manage music."
"Our customers have told us they don't want to download music to their work computers or phones because they find it hard to move music around to different devices."
Music files can be stored in MP3 or AAC formats. The service includes a "Cloud Player" - so you can listen to your library via a browser. Or you can use it to store text files, video files or anything else.
The service will be a challenge to Apple's grip on the music business. The company is already rumoured to be working on something similar and has the advantage of an awful lot of customers to sell it to.