This is true of most fabric stores.
Several years ago, Vogue/Butterick decided to take advantage of the system they already have in place at JoAnn Fabrics to do the same thing with books. It was a great way for small publishers to place their books in JoAnn, since they have so many 1000s of stores (it wouldn't be cost-effective for a small publisher to ship one or two books to each store, and would be a nightmare to keep up on). Butterick warehouses the books, and when each one sells, the store's POS (point of sale) system automatically reorders the book sold. This is how they keep patterns in the stores, too, in stores that do the consignment thing.
I know this because I was one of the first small publishers to take part in this program, and they may still have some of my books in the stores, although no more in the warehouse. Karen Maslowski in Cincinnati