I don't know why but my Spotify is always offline although i have full wifi. This happens only at home on my wifi (when i use data or another wifi it works good). I tried to restart the wifi router, delete & download app again, clear app data. Nothing helped. I turned my Spotify to premium 5 days ago and i have this problem for 3 days now. I didn't have any problem like this when i had only free version with Spotify. I don't know what to do next.
"1. Clear the app data. On your Android device: Settings -> Applications -> Manage applications -> Spotify -> Clear data
2. Uninstall Spotify. In the same screen, tap Uninstall
3. Restart device. While you're waiting, go to step 4 (this is the good part).
4. Retrieve your Spotify username and create your device password. This is DIFFERENT than logging in with your Facebook credentials. The Spotify username is really for OTHER devices (Sonos, Squeezebox, TiVo, etc.) but it'll work like a charm in this case too. Get it here: http://www.spotify.com/help/faq/devices/connect-devices/
5. Reinstall Spotify on your Android device
6. Log in with your SPOTIFY username (NOT your Facebook username). It will likely be 9 digits.