Traditional marketing refers to the following marketing instruments: price, place, product and promotion. These instruments are intended to position (that is, to market) a product or service in the market and to enable clear and unambiguous communication to that market. The price is usually determined by the cost price and the possible market price; the place of sale is a distribution policy with sales outlets; the product is an entity with value, as well as physical and virtual properties; and the promotion is usually mass communication using mass media and generic product-based promotional activities. This approach was defined in the 1950s and elaborated upon by, for example, Philip Kotler in his book Principles of Marketing. The marketing strategy is based on the definition of these marketing instruments, and the relationship between the products (or business) and market (or target group) forms the guiding principle.