29 C.F.R. § 779.207

In the case of an enterprise which has one or more retail or service establishments, all of the activities which are performed for the furtherance of the common business purpose of operating the retail or service establishments are “related activities.” It is not material that the enterprise sells different goods or provides different services, or that it operates separate retail or service establishments. As stated in the definition, the enterprise includes all related activities whether performed “in one or more establishments.” Since the activities performed by one retail or service establishment are the “same or similar” to the activities performed by another, they are, as such, “related activities.” (See Senate Report No. 145, 87th Cong. 1st Sess. p. 41.) For example, in operations of a single retailing business a drug store may sell a large variety of different products, and a grocery store may sell clothing and furniture and other goods. Clearly all of these activities are “related.” Similarly it is clear that all activities of a department store are “related activities,” even if the store sells a great variety of different types of goods and services and even if, as in some cases, the departmentalized business is conducted in more than one location, as where the department selling garden supplies or electrical appliances is located on separate premises. Whether on the same premises or at separate locations, the activities involved in retail selling of goods or services, of any type, are related activities and they will be considered one enterprise where they are performed, through unified operation or common control, for a common business purpose.