View: https://www.youtube.com/watch?v=_AJO8Cmyi4U
I stumbled upon this video the other day and decided to take the plunge since it's only $30 + tax w/ shipping. Sure enough, once you get it setup, it works controlling Spotify on my desktop.
This is great for me since when I'm working from home, I'm remote desktop into work which means the Spotify interface for me isn't immediately available and I'd have to go back to my desktop to get to it. Even voice commands work too. It's nice having a dedicated interface to control Spotify without having to swap back to it on your desktop. It even works with the free version of Spotify so there's no need to subscribe in order to use it. I imagine there's other situations where this could be handy too like maybe while playing a game.