I didn’t exactly imagine them being a demographic big into a big box furniture and interior decoration store. Ikea, maybe.

Not even furniture, really. It's more like sheet sets, comforters, bed skirts, faddish kitchen utensils, small cheap appliances, towels, toothbrush racks, etc.

I expect a lot of BBBY nuts are the "mattress on the floor with no fitted sheet" type, but they probably spend money on desk/chair and living room media furniture.