This may be of interest-
WHY DOES MANGA SUCCEED WHERE AMERICAN COMICS FAIL?
These were the key differences they found that contributes to manga's success:
1) CULTURE & HISTORY: For hundreds of years Japanese people have loved art similar to modern manga, such as scrolls, woodblock prints, or sketches. Those art forms primarily are composed of line drawings, and often are fantastic, violent, erotic, humorous, and narrative in structure.
2) TRAINS: The crowded, fast-paced, modern commuter culture of Japan's urban lifestyle has had a gigantic impact on the proliferation of Manga. Today a huge number of people in Japan spend a great deal of time on trains.
3) LANGUAGE: There are aspects of the Japanese system of writing that help contribute to a pre-disposition towards the sequential medium. The Japanese ideograms used in Japanese writing are a type of cartoon.
4) FREE EXPRESSION: The Japanese Comics Industry has never dealt with anything resembling the American Comics Code Authority. This freedom of expression has allowed them to enjoy a greater level of freedom, creativity and expression in their art.
5. DIVERSITY: Manga explores varied subject matters. Unlike the spandex-happy US market, Manga covers anything from sci-fi action to private school girls to basketball and every form of weirdness in between. There’s literally something for everyone to enjoy when it comes to Japanese Manga.
6. PRODUCTION: Manga is done cheap and fast, printed mostly on newsprint, and published weekly instead of monthly.
7. MARKETING: No comics-shop love here. Manga are sold on newsstands, at book shops and at kiosks all over Japan.
8. DISPOSABLE MEDIUM: The Japanese Manga Market is largely a disposable one, as opposed to the “Collector” mentality that dominates the US market.
#5-8 are the ones I think are stifling progress here.
I would also add-
9. WIDER AUDIENCE: American comics are geared towards a narrow demographic, generally 20-40 year old males.