Suppose that you have a graphic novel that you want to do; a manga graphic novel that you really believe in. But you're having trouble. Publishers aren't that interested in it, or, maybe they are, but you want complete control over your creative vision. You might consider self-publishing.
Now, there are two ways to do that right now. Electronically, or in print. Print has some real challenges, if you're going to go that route. With print, you have to take returns from the store. They send it back to you if no one buys it. You have to ship it to them. You have to make it, which is even more expensive. And the worst of all, most retail bookstores will not stock on the shelves, a self-published book. Why? They have just so much shelf space, and no more. They need to make sure that every author's book that they put on that shelf, is a good selling author with a track record, if they can help it.
However, on the other hand, in cyberspace, there is no bookshelf. Retailers can stock everything they want to. There's space for you. There's usually not that resistance. You don't have to ship anything to anybody. You don't have to take returns. It's cheaper to make than a print book. And instead of taking a year, or a year and a half for it to get produced and published, an e-book can get made and published in months.
Many online retail stores, even very, very big ones, will stock your e-book, even if it's self-published. But in cyberspace, there's unlimited shelf-space, so you have a better shot of being listed. Now if I were to go the electronic way, what I would suggest first, is try to serialize your graphic novel on a website. That way, you can get feedback from your readers. You can adjust it, change it a little bit, maybe discover that they like Character A more than Character B, and maybe try to feature that one more.
You know, this is the wave of the future, especially for comics, because there always have been successful self-published comic book authors, whether it's manga or American comics.
So, these are several options, I hope this has been helpful.