The interesting part is that aside from new arrivals and nonfiction, which are mostly grouped by category, adult fiction was arranged by publisher rather than by genre. Ace to Zebra, in other words (although Zebra was probably with other books from Kensington; I didn't pay attention). Books from different but related imprints (part of the same company division, maybe?) were shelved together - Ballantine and Del Rey, for instance. Those from Knopf and Crown, on the other hand (both Random House imprints, different divisions), are not. Within each publisher group, books are grouped by format (hb, pb, tpb), and then arranged alphabetically by author.
Yes, I tried to figure out the system; it's the librarian in me, I admit. I think it's probably based on how books arrive at the store, so it makes unpacking easy.
The store has a self-service kiosk where you can look up a book and find out who the publisher is, plus a customer service counter, where you could ask a human being about it. The shelves themselves were of the utilitarian, tall, metal, open-backed type. The overall selection was excellent, once you dug deep enough.
I was bemused by the arrangement, since it doesn't facilitate browsing for the majority of folks (who won't know the details on who-owns-who in the publishing industry, and don't care who published what, either). It allows for an odd sort of serendipity, and I guess it must work - the place has been in business for years - but I didn't see anyone else, besides me, browsing the shelves.