During the 1990s, he started Fatbrain.com , an online bookseller of professional and technicaltitles (he sold the company to barnesandnoble.com in 2000).
It was a big jump from hard-core technical books with titles like Applying RCS and SCCS, to Parisian guide books, but as a sole owner O'Reilly was able to finance his dream.
They're also stuck attempting to sell both formats while movie studios are still reluctant to release AAA-titles on either as they figure out the technical aspects.
On the technical side, the GBA was the rough equivalent to the Super Nintendo making ports of titles from that system easy, but the GBA also benefited from some wildly original games like Advance Wars.