Spotify has taken the world by storm and rightfully so, as it’s the first online music streaming service to really give iTunes a run for its money. What started off first on iOS and Android, and more recently received Beta love on BlackBerry, has successfully made its way over to Windows Phone 7 and will be live in the marketplace later today. What is Spotify? Spotify allows users to stream free ad-supported music from a computer. But you want to go mobile? No matter, to activate service from a mobile device requires a $9.99 monthly subscription option. The monthly fee also gets rid of ads and allows users to store playlists on a mobile device for offline playback