Amazon Cloud Player can stream and download your music library to as many as 10 PCs and mobile devices, which for some users is more than enough. But if you're a tech junkie and/or you share that library with family members, you might be surprised how quickly you hit that limit.
Indeed, if you own a PC, a smartphone, a tablet, a Roku box, and a late-model Ford (seriously), you might already be halfway to your device cap. For me it was a case of older devices I was no longer using, but had forgotten were still connected to my account.
If you're in a similar boat, you can easily remove extra, unwanted devices from your Amazon MP3 account. However, be sure to plan ahead -- like, way ahead. When you deauthorize a device, it takes 31 days(!) for that spot to become available for another device.
Step one: On your PC, open your browser and sign into your Amazon account.
Step two: Mouse over the Your Account pull-down menu, then click the Your Account entry. (Should be the very first one.)
Step three: Scroll down to the Digital Content section, then click Your Amazon MP3 Settings.
Step four: Now scroll down to Manage Your Devices and click Deauthorize next to any you no longer need. Don't be surprised if you see some strange names accompanying each entry; Amazon will assign something fairly generic unless you manually name your devices. (You can do that, by the way, just by clicking Edit alongside any one of them.)
Remember, it takes 31 days for a slot to open up, so if you're planning to buy, say, a new Kindle tablet with the intent of streaming your tunes, make sure you've got room at the 10-device inn.