There are as many definitions of marketing as there are companies trying to practice it. At an elementary level, it revolves around the oft-mentioned four Ps of product, price, promotion and place. These are the four tools that the marketer controls and can use to satisfy his or her customers. But, in order to get marketing to work for a hotel, it needs to go to the next level of understanding. This involves mastering three other essential marketing concepts: the marketing principle itself, market segmentation and product differentiation.