I honestly had no idea.
Today I finished reading Mariko Tamaki's wonderful graphic novel Emiko Superstar, which I gleefully put on my Goodreads. I do love to see the list add up. :D Then, in reading others' reviews of this wonderful volume, I found out that Minx-- the lovable girl-powah graphic novels line from DC Comics -- bit the dust. And not even recently. This was last fall.
Was it the economy? Was it the storylines that were relatively clean (read: low on parental piss-off factor)? Was it the "rumor" that girls don't read comics?
It wasn't for lack of hype. The New York Times was a fan. They got accomplished, award-winning authors like Tamaki, Cecil Castellucci, and Andi Watson to write the stories. And the books themselves were pretty well-received.
Guys, tell us these things. If sales were so murderously disappointing, then let librarians in on the secret. We'll buy those copies off you. Okay, maybe not all of them, but I do think we could rise as one and slay the rumors that these inspiring and enjoyable comics weren't good enough.