Or at least superhero comic books, because the last 4 years UK box office featured between one and three proper superhero movies in the tearly top tens, and The Misfits was one of the top local tv shows.

As Hibbs' humorously said, "He's a pretty popular fellow."

Sorry, I should have specified it was just comics I was talking about.

So, the question Marvel and DC need the answer to is HOW do you get all the people who go and what the movies to read the comics? Or perhaps (as I and I know MRP suspect) they don't care who reads the comics, as long as the properties are viable for other media.

Incidently, I'd assume right now the most popular book without multimedia exposure is Ms. Marvel (though she may be on the Spiderman cartoon now).. no one else is close. I'd guess Daredevil a distant 2nd. On the DC side.. maybe Batgirl (if that counts)

We don't have the same activities though, US Football, Baseball and even Basketball are all part of popculture here and the interest else where is nearly non-existant, meanwhile sports like Soccer, Rugby and Cricket are huge in the UK, Australia and else where but are nearly unknown here. And while there are some musical artists with a global reach like U2, Sam Smith and the likes of Taylor Swift, Rihanna and Beyonce the majority of each countries top artists is different. And popular TV that people talk about around the water cooler at work? Outside of maybe something like the Game of Thrones there is very little crossover to speak of.

And style of dress is different as well, for instance sneakers are probably the most common shoe for both men and women in the US but in mainland Europe unless I was in the gym I hardly ever saw a woman in sneakers and even in men it was uncommon to see them in sneakers and further there were two different bars that I tried to get into in Paris that wouldn't even let me in because I was wearing sneakers. Cargo shorts and over sized sweat shirts are also popular style here and again are seldom seen else where and probably one the most popular style items for men in the US is the Baseball cap which is also rare in other parts of the world.

Movies tend to be the rule breaker however as what is popular in the states on film tend to be popular elsewhere too but one thing does not make a global mainstream of pop culture.

As for comics, yes the US market is still the focus for Marvel and DC. Other than Batman: Europa I don't think there is currently a single comic being put out by the big two set out side of the US and there are no real big name heroes that are from outside the US outside of Wolverine. Their plots largely mirror US culture, when they make political references they are focused on US current events, and if they reference pop culture it's US based as well...and I don't see how that would mean there wouldn't be Vertigo as there are other tastes these publishers cater to as well, they just don't put the focus on them to the extent that they do on super heroes.

And the review Hibbs gave isn't deeply flawed, it isn't an absolute snap shot of sales outside of the direct market as not every store uses book scan but many of the larger distributors like Barnes and Noble do so with that sample size one could reliably assume the US market as a whole isn't that different. And DC's highest dollar book was a mask/comic combo set, not it's best seller there's a difference there and they were not far away from the top seller's list as their highest hit was #27 which can hardly be said to be far from the top of the heap.

Sports : all team sports developped by WASPs and televised, everyone aware of all of them, same companies advertise through all of those.
Flavor of the day biggest mainstream singers are present in all western top billboards
Macdonalds and Pizza hut are everywhere
Nike and Addidas are everywhere, andeven if some very unmainstream spots in Paris don't alow sneakers, same goes with some places in NYC...
Game of Thrones and The Office are everywhere (they make local versions of so many successfull TV shows now, like The Bridge, The Killing, Homeland or even Breaking Bad)
Same companies own almost all of western medias.
Brand loyalty is global, as are those brands, therefore the expression of a mainstream culture in our media society.
English language is also a pivotal part of that mainstream culture.
I don't percieve mainstream as pejorative, so I really don't see where you're going with all hte cultural exceptions/specificities

Bottom line, the same type of food clothe and hobbies are available and mainstream in all of the mainstream world.

About DC and Marvel focus being solely on the US market supposedly because they only publish one comic where the action is set there, I don't know what to answer you if you really feel that way. Of course I'm not talking about editorial geographical numbers, hahaha! I'm just saying that as with movies, DC and Marvel are fully aware thatinternational sales are as important as US ones, if not more. Many european comics have american characters and stories set there, yet they are mostly marketed towards the local market. I really fail to see the logic of your argument.

And about the report being deeply flawed, when it's author self accounts that amongst other faults, the amount of reached bookstores might just be 50% lower than their believed 85% reach of bookstore chains, excluding any indie store or online bookclub/independant dealer or libraries, well yes I assume those numbers are just a deeply flawed statistical tool, an interesting one nevertheless