This is by no means scientific. I put this together based on the music scrobbling service, Last.fm. This service is used word wide. On there, each artist has a page with various statistics. I want to focus on the number of plays and listeners from those pages. I have selected a group of metal artists and non metal artists and let's see how they compare.
Anthrax
Plays: 22.7 M
Listeners: 887.7 K
Megadeth
Plays: 85.8 M
Listeners: 1.5 M
Slayer
Plays: 72.3 M
Listeners: 1.5 M
Metallica
Plays: 244.9 M
Listeners: 3.3 M
Motorhead
Plays: 53.6 M
Listeners: 1.6 M
Judas Priest
Plays: 52.7 M
Listeners: 1.4 M
Iron Maiden
Plays: 148.6 M
Listeners: 2.4 M
Taylor Swift
Plays: 114.7 M
Listeners: 2.4 M
Michael Jackson
Plays: 113.8 M
Listeners: 3.7 M
The Beatles
Plays: 457.5 M
Listeners: 4.1 M
Lady Gaga
Plays: 228.9 M
Listeners: 4 M
Radiohead
Plays: 423.8 M
Listeners: 5.4 M
It is interesting that Anthrax has the fewest plays and listeners in comparison to the other major metal bands listed. It's also fascinating that newer artists have a significantly larger fan base than these metal artists on this list who have been around for decades. I think this is a pretty good sampling.
Anthrax
Plays: 22.7 M
Listeners: 887.7 K
Megadeth
Plays: 85.8 M
Listeners: 1.5 M
Slayer
Plays: 72.3 M
Listeners: 1.5 M
Metallica
Plays: 244.9 M
Listeners: 3.3 M
Motorhead
Plays: 53.6 M
Listeners: 1.6 M
Judas Priest
Plays: 52.7 M
Listeners: 1.4 M
Iron Maiden
Plays: 148.6 M
Listeners: 2.4 M
Taylor Swift
Plays: 114.7 M
Listeners: 2.4 M
Michael Jackson
Plays: 113.8 M
Listeners: 3.7 M
The Beatles
Plays: 457.5 M
Listeners: 4.1 M
Lady Gaga
Plays: 228.9 M
Listeners: 4 M
Radiohead
Plays: 423.8 M
Listeners: 5.4 M
It is interesting that Anthrax has the fewest plays and listeners in comparison to the other major metal bands listed. It's also fascinating that newer artists have a significantly larger fan base than these metal artists on this list who have been around for decades. I think this is a pretty good sampling.