Robin Brenner has a very interesting post up at Good Comics for Kids, where she does some number-crunching with her manga and graphic novel circulation statistics. The most popular series aren’t what you might predict, which shows why it pays to pay close attention to circulation and patron requests when doing collection development for this type of library collection.
I haven’t tried out this database myself, but I thought it was interesting that Alexander Street Press is putting out a database dedicated to comics and graphic novels scholarship. The focus is on underground and independent comics. This looks like it will be worth checking out for anyone doing academic research in this area.