Henry recently set up a retail store in his hometown. He studied the pattern that other store-owners followed in obtaining new customers. All their current customers had referred the store to their friends and family. Their awareness basically spread through word-of-mouth. Henry knew that his store offered the same quality as the other stores did. His store was also on the same street as the other retail stores. Given the setting, the other store-owners were already charging their customers the bare minimum in order to remain competitive. Which P of marketing should Henry concentrate on to distinguish his retail store? Henry should concentrate on _______ to distinguish his retail store.