Industries that may have difficulty identifying their end-user customers

Identify three industries that may have difficulty identifying their end-user customers. (Refer to the textbook examples, but do not take the examples straight from the book). (Due: Sunday) Industry 1: What makes identifying customers difficult in this industry? Why is it important for the industry to identify its end-users? How would the industry approach identifying its end users? Industry 2: What makes identifying customers difficult in this industry? Why is it important for the industry to identify its end-users? How would the industry approach identifying its end users? Industry 3: What makes identifying customers difficult in this industry? Why is it important for the industry to identify its end-users? How would the industry approach identifying its end users? You might want to discuss different approaches to identify end users by industry category.