I've been scouring the Web for hard numbers on graphic novel sales in US bookstores (as opposed to those through the direct market), but none have come up. Just a few articles on Publishers' Weekly. The marketing research firm Nielsen has their Bookscan service which provides a good sampling of bookstore sales figures, but you have to sell your soul to get the data. The closest I ever got was this list from Amazon, featuring the top 25 "graphic novels" of 2003 based on Bookscan, sans the numbers. It should come as no surprise that manga (particularly Chobits) dominates the list. Volume one of The League of Extraordinary Gentlemen and Sandman: Endless Nights are in there.
The New York Times' lengthy early-July feature on graphic novels stated that Marjane Satrapi's Persepolis, the autobiographical tale set in war-torn Iran, has sold 450,000 units so far, while Chris Ware's Jimmy Corrigan hardback has drawn in 100,000. This suggests the strength of graphic novels in capturing a sizeable book market share.
In Butch Dalisay's September 2000 commentary in Cyberdyaryo, Karina Bolasco was quoted to have pinned the Philippine book market at around 810,000. In a September 2002 article in Publishing Trends, Lirio Sandoval pegs the potential local market for books at 30% of the population, a humongously larger 20+ million. Despite my idealism, I'm looking at only 2 million.
These numbers are important to me because they give me an idea how far a local graphic novel, which is physically a book, can go in this country. Almost everyone I know who's been making comics is having a hard time, marketing-wise. Let's say that the numbers help me deal with my floundering faith. I think any local grafictionist would be thrilled to get even 1%, or 20,000, to buy their work.