With April sales numbers released from Diamond Comic Distributors, a subtle pattern has revealed itself: Dark Horse has reclaimed its position as fourth-largest publisher from IDW Publishing for three months straight. It's a streak of growth in market and dollar share that hasn't happened for Dark Horse since fall 2011.

It's great news for an industry mainstay that seemed to be getting eclipsed by the younger IDW at its own game of mixing licensed properties with creator-owned titles. Whether it's temporary or not, digging into the sales charts, it's clear there's more stability in Dark Horse's catalog than there might first seem.

Obviously Star Wars is the property many know the company for, and when it was announced the license would move at the end of this year to Marvel, some worried how Dark Horse would carry on. However, most publishers realize that no license is forever, so Dark Horse has built a diverse library that seems to be lifting it up now. Despite such diversifying, Star Wars is still the big seller at comic shops, but it's only the beginning. The back-to-back launch of The Star Wars, a comics adaptation of an early draft of George Lucas' screenplay, and a back-to-basics Star Wars by Brian Wood provided two accessible titles; if you'd ever seen the original Star Wars trilogy, you're all set. The last issue of The Star Wars comes out later this month, with a collection in both hardcover and softcover to follow in July.

However, Dark Horse doesn't begin and end with Star Wars. In fact, those two titles have been eclipsed in sales by Serenity: Leaves on the Wind. Not only did Issue 4 outsell The Star Wars, but the reorders on the previous three issues have been adding about 3,000 to 4,000 in sales for each issue each month. It's also propelled sales on the collections of Dark Horse's previous Serenity comics, moving about 500 copies each of the two pricier hardcover collections for the past couple of months. Of course the other Joss Whedon properties, Buffy the Vampire Slayer and Angel and Faith, are also successful, but they're not having that same kind of trickle-down effect.

That kind of steady longtail, where it rises all of the boats of related titles, might actually be one of the secrets to Dark Horse's stealthy growth. The best example is the line of Avatar: The Last Airbender graphic novels by Gene Luen Yang, Gurihiru and the show's creators Michael Dante DiMartino and Bryan Konietzko. Since 2011, seven books have been released at $10.99 a pop, preceded by a $14.99 Lost Adventures graphic novel. There's also a hardcover that collects The Search trilogy; an eighth book is due in July. The art duo of Gurihiru masterfully recaptures the feel of the animated series, and Yang nails the characters and their world. Every month or so, the entire set moves another 500 to 600 copies. It's a strong performance that may not tear up the top of the charts, but it bubbles steadily along. Everyone loves to top the charts, but those kinds of evergreen sellers are the real victories -- and the bean counters love these kind of dependable sources of income.

And speaking of evergreen, the 2004 edition of Hellboy, Vol. 1: Seed of Destruction still shows up, moving 500 copies here, 1,000 there. Other random trade paperbacks will emerge with another 400 or so, like Hellboy, Vol. 7: The Troll Witch and Others, originally released in 2007. Twenty years on, and the entire Hellboy universe is going strong. In fact, speaking of that anniversary, the art book Hellboy: The First 20 Years looks like it might have legs. The first collection of Hellboy in Hell comes out today, marking the return of creator Mike Mignola as artist. It received a fair amount of press when the individual issues came out, so this is bound to do well too. Spinoffs seldom perform quite as well, but B.P.R.D. is a steady-seller. Even a divergent take on the character, like the kid-friendly Itty Bitty Hellboy by Art Baltazar and Franco, does a not-too-shabby 2,000 copies in the direct market, a number that was once unheard of for a trade paperback aimed at kids. Hellboy is Dark Horse's rock: It seems like it's always been there, and it's hard to imagine it not being around.

The graphic novel The Fifth Beatle: The Brian Epstein Story, by Vivek J. Tiwary, Andrew C. Robinson and Kyle Baker, has the potential to be a similar evergreen seller, too, although of a different pedigree. The acclaim it's already received puts the book more in line with something you might expect from First Second Books (in fact, that imprint released its own Beatles graphic novel Baby's in Black in 2012), so it probably has a stronger life in the bookstore market. Amazon's bestseller charts put it in the top 50 of three different categories, so there could be some truth to that. 47 Ronin has some potential to do the same, but it sadly doesn't seem to have gotten the early traction or buzz that I would've thought.

Another title that seems steady but I thought would be doing better is Conan. The once-hit Conan the Barbarian was relaunched as Conan: The Avenger by Fred Van Lente and Brian Ching, and it appears only to have rewound the slowly dwindling sales clock by a three or four months. Still, more than 10,000 copies for Conan is pretty consistent with how the property has been performing, and the Chronicles of Conan collections reprinting the old Marvel comics still do quite well, even at 26 volumes. In fact, every Conan collection steadily sells about 1,000 copies or more through Diamond.

Dark Horse has established a deep back catalog while continuing to bring in properties like Matt Kindt's Mind MGMT, Greg Rucka's Veil and its revived superhero line under the Project Black Sky umbrella.

It's not always high-fives and champagne, of course, but Dark Horse has a long-term, slow-and-steady strategy that appears to serve it well, serves the publisher well.