The rivalry between Marvel and DC goes back to the Golden Age of Comics (roughly 1938-50), when DC was still National Comics and Marvel was known as Timely Comics. But the real battle began in the late 1960s, when Marvel topped DC for the first time.

The two heavyweights have been slugging it out ever since.

In recent years Marvel has been Big Cape on Campus, more or less since it emerged from its late '90s bankruptcy and was bought by Disney (in 2009). It doesn't hurt that Marvel Films has virtually owned the box office with movies like "Captain America: Civil War."

Meanwhile, DC Comics shot itself in the foot in 2011 with a lame reboot called "New 52." While the idea was to make iconic heroes like Superman younger and hipper, the result was DC erasing some of the greatest stories in its own history. Longtime fans were not pleased. Realizing its error, DC tried another reboot in June called "Rebirth," which fixed many of its previous fixes. In addition to simply making the books better, DC reduced the number of titles it was publishing, while increasing the frequency of its better-selling ones.

This "less is more" strategy paid off. In July, DC pulled slightly ahead of Marvel in market share, according to numbers from Diamond Comic Distributors Inc. And in August, they dropped the hammer: DC's lead in market share over Marvel was more than eight points, 39.27 percent to 30.78 percent.

If your eyes glaze over at the sight of math, just take my word for it: That's a lot.

Where the carnage is really obvious, though, is in the Top 100 list. In August, Marvel only had one title in the top 10, three in the top 30 and nine in the top 50. DC had all the rest, except for Image's "The Walking Dead" at No. 13.

And it's not like Marvel hasn't been trying. They've had a big summer crossover going that's supposed to be dominating the charts. It just hasn't worked. It's called "Civil War II," and it's a sequel of sorts to the source material for the "Captain America" movie that just burned up the box office. While the main "Civil War II" title is selling very well, the tie-ins are not.

"Whatever its reason," writes Rich Johnston at bleedingcool.com, "whatever the analysis (and there will be plenty), despite having a movie on the screen, a Free Comic Book Day launch, the might of Disney and a far more able marketing department, 'Civil War II' is a bust."

But don't break out the crying towels just yet. Virtually all the publishers are still making pretty much the same money they were before DC's "Rebirth." That's because, while DC is gorging on market share, it's not really cutting into anyone else's profits. According to trade magazine icv2.com, "Rebirth" is bringing in, for lack of a better term, new money.

It's a rising tide, and it's lifting everybody's Bat-boat. But where is that money coming from? Is "Rebirth" bringing new customers into the comic shop? Are existing customers simply buying more books? Are retailers simply ordering more and getting stuck with product they can't move? The answer to that question will also answer whether the current sales trends are meaningful, or just a summer fad.