A drop in sales for graphic novels

According to ICV2 (via Anime News Network):

Graphic novel sales dipped in both bookstores and comic stores in the first half of 2009, according to an article in the new ICv2 Insider’s Guide #67. Nielsen BookScan numbers show an 8% decline in piece sales in bookstores in the Adult Fiction/Graphic Novels category in the first 25 weeks of 2009, according to the article. The Bookscan figures do not include graphic novels racked in Kids and YA departments in bookstores, which probably means that the decline is less than 8% over-all.

Graphic novel sales were up in comic stores in Q1, but dropped in Q2.

As I've guessed before, the graphic novels they allude to could be DC and Marvel's time-wasting crossovers and publicity stunts. That's why, now that I think of it, I wish they'd give some clearer insight as to just what graphic novels aren't doing well. It could help to understand what might be going wrong with GN sales.