ICv2 released the annual report on the manga market in North America. The yearly sales of Japanese manga in 2009 was $140 million, 80% of the previous year. The manga market has shrunk into two-thirds of its peak since 2007. In contrast, the sales of the non-manga graphic novels has made 40% increase in two years.
Chart of the manga market in North America (Total Graphic Novels = Manga + "US Cartoon")
ICv2 gave three possible reasons for the decline:
1. Female readers who established the shojo manga boom have grown out of the manga habit.
2. Effect of the illegal scanlations
3. Keeping on purchasing long series has become a burden for the fans.