Back then it was. The stockroom was not always in the building however, in some cases things were shipped direct to the customer. The Green Stamps redemption store was the same way.

My father actually belonged to a membership version of one of these clubs in the 90s. You would pay this huge membership fee, then go into a location that was nothing but hundreds of catalogs on the walls. You'd pick out what you wanted, filled out an order form, and it was shipped to you.