X Friend(s) Listen(s) to an Artist

[SpotifyUser53]

On the Android app (and I'm sure other places) there's a fun feature where you can see which of your Facebook friends listen to a particular artist. I would like to know how this is determined. How frequently do you have to listen to the artist (and in what time period)? Also, is there a setting that controls if you are shown?

I'm trying to figure out what my friends see about me.

Thanks.