Graphic novel sales down 15%

Adult graphic novel sales have declined by 15% in Q3 compared to the same period last year, according to market researcher Nielsen BookScan.

The decline is attributed to the popularity enjoyed by Alan Moore and Dave Gibbons's Watchmen in 2008's third quarter.

Sales of the graphic novel soared to record levels following the release of the trailer for the Watchmen movie in July 2008.

Though sales of the book remain high, they are significantly lower than they were this time last year.

The decline may be mitigated by sales of young adult and children's graphic novels, which are thought to be high and are not included in the data.