Drucker argues that if a business takes the time to first properly determine customer requirements and expectations, the products that it develops are more likely to be deemed desirable by the customers the business is targeting. The Chartered Institute of Marketing adds that marketing involves understanding customer requirements both now and in the future. Businesses must strive to satisfy their customers and make profits to invest in future products and market developments. The American Marketing Association’s definition hinges on the economic exchange that occurs when an interested customer purchases a product or service in return for payment or a donation. The AMA adds that marketing occurs in a dynamic environment, and that the exchange at the heart of marketing is made possible through the marketing mix (cf. Brief 32): product, people, price, promotion and place. The trading environment is prone to external pressures (cf. Brief 3), competitive threats (cf. Brief 34) and ever-changing customer demands (cf. Briefs 6 and 7), causing a set of dynamics rarely encountered by other business disciplines such as production, finance or human resources.