Even casual fans of superhero movies know that films based on Marvel comic book characters tend to kick ass while DC movies are hit-or-miss. But, outside of the big box office numbers, DC seems to be selling more actual comic books than Marvel. And, as pundits look back on 2017, this trend appears to have calcified. At this point, someone at a comic book shop is more likely to buy a DC comic than a Marvel comic. But why?

On Monday, Bleeding Cool reported that influential comic book store Challengers Comics + Conversation in Chicago recently openly tweeted about their sales figures. Specifically, the huge retailer noted that they were “down $21,000 in single-issue Marvel sales alone.” In a world where Marvel movies rake in serious cash at the box office— Thor: Ragnarok made 116 million in its opening weekend alone —$21,000 bucks might not seem like a lot. But, that’s just one comic book shop, in one city in America. If Challengers Comics is having a tough time moving Marvel issues, it stands to reason other people are too. Challengers also noted a general uptick in DC comics as well as merchandise.

But does this mean that DC is actually more popular in comic book stores in general? One store’s sales can’t tell the whole story. Or can it?

Over on Comics Beat, writer Todd Allen meticulously tracks comic book sales. When you dig into his analysis, you’ll come away with two obvious takeaways. First, if Marvel didn’t have Star Wars and DC didn’t have Batman, their relative sales would probably be equal. Second, as of October 2017, if you remove “special events” from any kind of sales data (for Marvel, this would include the controversial Secret Empire) DC does way better in overall sales of regular titles. Translation: it seems like more people buy Marvel comics if they’ve heard some crazy shit is going on (like Captain America being a Nazi) as opposed to readers buying DC issues just because they like those characters.

This isn’t to say DC has put Marvel in a position of becoming a beggar with a tin cup outside of your local comic book shop, but Allen’s observations combined with the anecdotal data from Challengers does pose an interesting question: do DC characters actually engender more loyalty from readers than Marvel characters? If we think about Allen’s suggestion about removing Star Wars from Marvel’s comic sales and Batman from DC’s in order to create a level economic playing field, there’s one important thing to remember. Batman is a character created by DC comics. Star Wars is a brand that just happens to be sold by Marvel at the moment.

Meaning, if Marvel comics is going to draw its readers back in, it’s possible it will need to remind those readers that they too, have some great characters you may have heard of. A few of them are starring in a big couple big movies coming out soon.