Personal service cannot be separated from the individual and some personalized services are created and consumed simultaneously.
Services cannot be separated from the service providers.
A product when produced can be taken away from the producer. However a service is produced at or near the point of purchase.
Take visiting a restaurant, you order your meal, the waiting and delivery of the meal, the service provided by the waiter/ress is all apart of the service production process and is inseparable, the staff in a restaurant are as apart of the process as well as the quality of food provided.