Its a preview and only working for paying users!
Spotify for Linux
This is a preview build of Spotify for Linux. As a preview release this version is still unsupported, but we're running it ourselves and will try to make sure it keeps pace with its Mac and Windows siblings, there are issues regarding decoding of local music on the Linux platform so we haven't included support for local files in this version. As we haven't found a reliable way to display ads yet, this version is only available to Spotify Premium and Unlimited subscribers.
Imho better use wine as suggested on official homepage of spotify