Don't need to install software. Can buy from anywhere, as long as you sign in to your Amazon account. MP3 format vs. AAC. Can play songs from web. Promotion

Don't need to install software. Can buy from anywhere, as long as you sign in to your Amazon account. MP3 format vs. AAC. Can play songs from web. Promotional prices on top sellers, so the #1 song on both sites is $0.69 vs. $1.29.