Were still not sure whether Amazons truly launching a music streaming service, but if it does, you might only be able to access songs and albums for a limited time. According to the Wall Street Journal, the e-commerce company hopes to offer music streaming as part of Prime to justify an annual membership (from $79 to $119) price increase. Unlike other services like Spotify or Pandora, Amazons end goal is to entice people to download tracks from its MP3 store, hence, the time limit.