It's easy to become so wrapped up in the monthly direct market horse race that we overlook success stories in other channels. Oh, not the bookstore performances of The Walking Dead, Saga or Attack on Titan; we get regular reminders of that from BookScan. In this case we're talking about Ninjago, the LEGO toy line turned animated TV series turned graphic novel line.

Although the debut of the latest book atop The New York Times bestseller list should've provided a clue to how well it's doing, Papercutz has trumpeted that with the release of LEGO Ninjago, Vol. 9: Night of the Nindroids, the series has surpassed 2 million copies in sales.

“LEGO Ninjago titles have been a phenomenon for us,” Papercutz President Terry Nantier said in a statement. “We’ve been back to press numerous times and it seems like we’re always struggling to keep up with consumer demand. I’ve been in the graphic novel publishing business for quite some time and I’d be hard pressed to name a lot of other kids ‘series that have hit that level of sales.”

Things are going so well that the publisher, perhaps unsurprisingly, is expanding the line in May with a series of graphic novels based on Ninjago "Legends of Chima" LEGO sets.