In addition to the Official Android Marketplace that you’re used to, you can now browse and download apps from the Amazon Android App Store. You can either do this online at amazon.com, or you can download the amazon app store app (try saying that 10x fast) to your phone and browse directly with your handset.
Why use Amazon App Store instead of the Official Android Marketplace?
1. The Current Promotion: Get 1 Free Paid App Every Day!…Amazon is promoting the opening of their App Store by giving away a paid app for free everyday. So if you’ve had your eye on some paid apps in the Official Android Marketplace, but have been holding out because you didn’t want to spend the $1 (you cheapskate!), then check back with Amazon on a daily basis to see if they are giving it away.
2. App Exclusivity: Amazon will have some apps exclusively, which means they won’t show up on the Android Marketplace (whether this is a temporary or permanent thing remains to be seen)
ex. Angry Birds Rio
3. Payment Preference: If you’d rather pay/checkout with your Amazon account than with Google checkout, then the Amazon Android App Store is for you. This might be handy if you have Amazon gift cards/coupons lying around.