“This activation encourages users to create their custom setlist by dragging and dropping Troye’s most popular songs and then sharing the results on Twitter or Facebook.  The prize is a flyaway to Las Vegas (sponsored by iHeartRadio) and a chance to have Troye perform the winner’s setlist.”

[Note: Setlists aren’t playlists per se but a key part of their backstory w/related fan dynamics for contests.]

Source: Troye Sivan iHeartTroye Sweeps – Metablocks