There are multiple metrics meant to measure the artist's audience on social or streaming platforms.
On Facebook, we have followers and fans
The difference between the two is that we like the page to be fans and follow the page to get the latest updates.
We only display Facebook fans (= likes) on Soundcharts, located in the overview of an artist's profile, though the metric may not be visible on the artist's Facebook page.
On Spotify, there are followers and monthly listeners
Spotify followers like or follow the artist's profile.
We display Spotify followers here:
Spotify monthly listeners are the unique listeners who play the artist's music during a 28-day period. More about this can be found in Spotify's help article.
Here is where we display Spotify monthly listeners: