User blog comment:DaNASCAT/Technical Update: September 16, 2015/@comment-25648422-20150919115112/@comment-126761-20150921142215

The Spotify documentation says:
 * When a logged-in Spotify user clicks the button, the music will start playing in the Spotify player. If the user is not logged into their Spotify account, they will be prompted to do so. If the user does not have a Spotify player they will be sent to the Spotify sign-up page or prompted to download a suitable client, in a new window.

Does this cover your experience?