Currently, the app for WP isn't free (yet). Spotify said this will change in the future, however, we haven't seen nothing yet.
U can find more information here:
[WP8] Bring Spotify Free to Windows Phone
I think they should change this ASAP + bring some more features.
Last.fm: RockYourSocksxX
Not a shred of evidence exists in favor of the idea that life is serious.
• Brendan Gill
