The end of the Golden Age is the investigation into comics in the Senate in the early 50s and the disappearance of the superhero from comics.

The defining moment that ends the Silver Age is up for debate, no one can agree when it was. The two most common moments argued over is the death of Gwen Stacy in Spiderman and the Green Lantern/Green Arrow team-up and foray into social consciousness....

I think the Green Lantern/Green Arrow series by Denny O'Neill/Neal Adams (One Sixties Issue Per Issue) marks the end of the Silver Age.

the Green Lantern/Green Arrow team-up and foray into social consciousness....

Sheesh, you'd think there was some kind of hive mind going around these parts.

At its height during WWII, Superman's circulation was over one million copies.

Today, a best-selling comic typically doesn't sell much more than 100,000 copies.

[edited to revise my figures]

Not a, but THE best selling comic of any given month maybe cracks 100K. And that has been a relatively recent return, for a while in late 90s, early oughts, no one was break 75k.

Last time there was multiple titles cracking 100k was in the early 90s speculator bubble.

Then there's Bronze Age, which goes up to about Crisis, IIRC.

Though with Bronze and the seldom-mentioned Copper, it kind of feels like they're just slapping a metal where appropriate or something.

nods head vigorously in agreement with definitions

Kevalier and Clay is all about the Golden Age, for instance, up to and including it's end.

Then there's Bronze Age, which goes up to about Crisis, IIRC.

I don't know that many people who use Bronze Age as a term. It's usually either just Pre-Crisis or Post-Crisis. As you note, it's just a long slide into the base metals at that point.

Other historical markers (in my mind anyway) that mark signal changes in the industry would include things like: Cerebus and Elfquest establishing direct market comics distributed through comic stores instead of 7-11s; Alan Moore taking over Swamp Thing (which ultimately kicks off the Vertigo Line and a whole new market); the media hoopla about Dark Knight, and Miller's Batman Year One reboot; Fantagraphics publishing Love and Rockets (another significant expansion in the market for comics, coincident and tied with indie culture in general); a couple weird rise-and-fall cycles of the industry driven by collector speculation (first the black and white crash by Teenage Mutant Ninja imitators - there were fourteen at one point. Then the Every Comic Is Now Officially #1 Forever, with Multiple Gold Leaf Embossed Covers Collect Them All). Etc. etc.

So what would the line of comics that came after Miller's Dark Knight be considered? Are they Bronze Age or Titanium or just, oooooh dark and nifty?

I'm considering getting back into comics again. I stopped buying X-Men after it split into half a dozen X-titles (or so it seemed to my wallet). I read all of Sandman when it first came out and a hundred or so issues of Hellblazer before I got distracted by something shiny. But I picked up an Ultimate X-Men Ultimate-Spiderman crossover and really enjoyed it.

I don't know that many people who use Bronze Age as a term.

I think eBay might.

So what would the line of comics that came after Miller's Dark Knight be considered? Are they Bronze Age or Titanium or just, oooooh dark and nifty?

"Copper"

Yeah, I don't get it either.

If it's post-Clinton, it's "modern."

Note, these distinctions are usually only seen at places attempting to sell you stuff. Well, bronze is kinda-sorta used. Kinda.

But the main distinctions I see out there are Golden Age/Silver Age/Modern Age.