Of course they are.
I'm only asking because I have a bookkeeping dilemma. I've always had separate keys on my register for graphic novels and books. But they are getting harder and harder to separate.
I've noticed, for instance, that when Sabrina works, more graphic novels and less books are sold, and when I'm working, it's the opposite. While this is probably somewhat true, I suspect the main reason for the discrepancy is that, when in doubt, she presses the "graphic novel" button and I press the "book" button.
For me, the decision is often decided on the basis of where I ordered the book. Since I'm ordering more and more titles from my book distributors, this gives the advantage to the book category.
We also have a lot of "pop culture" art and reference books, which bridge the gap between the two categories.
I suppose it doesn't really matter which button is pushed anymore. They are, indeed, all "books."
The second part of the question is a matter of description to the customers. I often tell nervous parents that graphic novels are a good choice because they are what their kids want to read. My feeling is that it's important to get the idea of books as entertainment across. They'll bridge the divide on their own.
I have no evidence of this, but a very strong feeling.
I cringe sometimes when I see parents either refuse to buy their kids a book and/or make it some kind of chore.
But more to the original point--even saying the graphic novels will help kids transition to prose novels is somehow qualitatively separating the two.
I'm currently reading a nice thriller. Fun to read. But I'll tell you this--it has far less content than, say, a "Sandman" graphic novel, or a thousand other graphic novels.
Form does not dictate content. Art and words together can, in my opinion, have more of intellectual stretch to them than your average "guilty" pleasure read. (Not that I believe any book is a guilty pleasure.)
If I really wanted to know what I was selling, I'd probably do 4 or 5 categories: young adult, regular fiction, genre fiction, (as if I could ever figure out the difference....), pop culture, and art books. But I know that me and Sabrina are so habituated to the categories that we have that it would be very difficult to do that.
I suppose I'll continue to separate the two categories if for no other reason than to keep track of what I'm ordering, but the truth is--it doesn't really matter. A book is a book.