Metallica has sold over 100 Million albums worldwide, over 55 million in America alone.
Van Halen has sold over 50 Million albums in the US alone
Iron Maiden has sold over 70 Million albums World Wide
Judas Priest has sold over 30 Million albums World Wide
they are not that extreme, but those four bands have sold WAY OVER 250 Million albums together.
When it comes to extremes
CANNIBAL CORPSE: 558,929
DEICIDE: 481,131
MORBID ANGEL: 445,147
SIX FEET UNDER: 370,660
OBITUARY: 368,616
DEATH: 368,184
NAPALM DEATH: 367,654
CARCASS: 220,734
ENTOMBED: 198,764
The top-selling death metal albums of the SoundScan era are as follows:
MORBID ANGEL - "Covenant" (1993): 127,154
DEICIDE - "Deicide" (1990): 110,719*
DEICIDE - "Legion" (1992): 103,544
OBITUARY - "The End Complete" (1992): 103,378
CANNIBAL CORPSE - "The Bleeding" (1994): 98,319
*note - Most Death Metal albums don't get sold through large chain stores, so many of the album sales can't be counted through soundscan
When it comes to Metalcore and Hardcore
Trivium certified gold with Ascendancy and Silver with The Crusade in the UK
All That Remains has sold well over 100,000 albums in the us, and peaking on the US Billboard charts at 75
Lamb of G-d has sold over 1.1 Million albums in America, Peaking at Billboard Chart # 8
Chimaira has sold over 200,000 Albums in the US
And without regard to specific genres
Pantera, Megadeth, Slayer, KoRn, and SlipKnoT have each sold MILLIONS OF ALBUMS
so obviously they are fairly popular ( including many extreme metal bands ), and have sold very well
Metal has been around since the late 60's/early 70's and still sells well, has a strong following, and is literally growing every day.
Ozzfest is ONE of the biggest and best selling festivals every year, if not the biggest.
The Tuska Open Air Metal Festival is a huge festival in Norway that shares the stage with many extreme metal bands
Another huge metal festival, with mostly Extreme Metal Bands is the Wacken Air Festival
So I have just proved ( whoever it was ) wrong about Metal not going to last, and just being on the fringes of rock.
Metal is its own genre with its own fans, and it is huge, even without as much air play as rock and pop.
And so you all know, screaming, growling, and even pig squeals take practice to do PROPERLY. Sure, these kids on youtube can do them, sure your grandma could do them, but how long do you think they can do it without losing their voice or permanently damaging their throat?
My singer, Malcolm, spent years working on his screams. When he began he sounded worse than the fatty in the youtube band we all made fun of, but he learned to sing and worked on screaming and his range, and now he is the most versatile screamer I know. He has a broader range in pitch for screams and growls than most SINGERS I have ever heard, EVER. This includes professional and unprofessional. He also has more control than almost any singer I have ever heard. He can choose how gritty or clear he wants his voice, and he can control his volume, from quiet to ear-piercingly loud, without a mic. He can go straight from All That Remains to Cannibal Corpse to Cradle of Filth right into Metallica at the drop of a hat.
And, if I haven't mentioned already, he can sing as well.
And not all metal is screaming anyway.
And obviously, there are decent metal bands and bad ones, same with rock. Saying all metal bands sound like that fatty's band from youtube is like saying all rock bands have as much talent as nirvana.
I am going to give all the nay-sayers a challenge. Watch each of the videos below, and find three other bands of each genre and sub-genre listed. Only after that will you have discovered a small portion of the tip of the ice-berg that is metal. And after that, compare those bands to the original band that we were all laughing at.
* note - You will hear similarities between some of the bands first in the list, but also many obvious differences.
* note - this list is very incomplete. There are dozens more sub-genres but I have been sitting here an hour finding example videos.
Power Metal - Stratovarious
http://youtube.com/watch?v=lNLdTfwx5ZQ
Modern Power Metal - Cellador
http://youtube.com/watch?v=7X7hr-Ky8tg
Extreme Power Metal - Dragonforce
http://youtube.com/watch?v=q3M2X4ZAH_w
Modern Epic Power Metal - Kamelot + Simone Simons of Epica
http://youtube.com/watch?v=CDNWu0CV9Ro
Neo-classical Metal - Racer X
Invalid Link Removed
NWOBHM ( New Wave of Brittish Heavy Metal ) - Iron Maiden
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80's Thrash - Metallica
http://youtube.com/watch?v=oCE1NnvonF0
Modern Thrash - Children of Bodom
http://youtube.com/watch?v=hjZXUyvFQDA
Progressive Metal A - Symphony X
http://youtube.com/watch?v=9k4Sm1PN9cE
Progressive Metal B - Tool
http://youtube.com/watch?v=N_c60Sp7Gtc
Early Death Metal - Morbid Angel
http://youtube.com/watch?v=wvfoePd5mnk
Melodic Death Metal - Dark Tranquility
http://youtube.com/watch?v=yCeRS3nhSKE
Thrashy Death Metal - Deeds of Flesh
http://youtube.com/watch?v=l48nxx3T5hE
Scandinavian Death Metal - Arch Enemy
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Progressive Death Metal - Opeth
http://youtube.com/watch?v=MjrnMgrHR3A
Brutal Death Metal ( Gore Metal ) - Cannibal Corpse
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Blackened Death Metal - Goatwhore
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Black Metal - Dimmu Borgir
http://youtube.com/watch?v=j8bUs0eqHYY
Doom Metal - Black Sabbath
http://youtube.com/watch?v=gbxfe7DMxVo
Epic Doom - Candlemass
http://youtube.com/watch?v=-3uvf0cn0jo
Drone Doom - Sun O))))
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Funeral Doom - Skepticism
http://youtube.com/watch?v=LBqspw3NcpE
Grindcore - Napalm Death
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Early Metalcore - Nuclear Assault
http://youtube.com/watch?v=aWFhlYfqj4Q
Modern Metalcore - Trivium
http://youtube.com/watch?v=43Ck866mmm8
Industrial Metal - Fear Factory
http://youtube.com/watch?v=eWB3T-GlK9k
Techno Industrial - Rammstein
http://youtube.com/watch?v=1_JaPdqd5Aw
And until you have listened to each of those, and listened to more bands of each genre, you can not truthfully state that you know enough about metal to judge it.
And as I said the list is very incomplete, there are other genre's such as hardcore, post-modern hardcore, death grind, technical death metal, southern metal, operatic metal, etc.
and btw, I started this post at about 2:00 and it is now 3:44