If you buy only one guide to marketing I would recommend this. At over 400 pages it's quite a read but its best used as a reference book rather than a management fad book you can take on the plane. Don't read it in one sitting! It's main advantages are the very complete checklists for everything from strategy formulation to agency evaluation and from pricing to positioning. These can help you make an immediate difference in the office from day one. It's good for students - (much preferable to Kotler for example because whilst Kotler is more wide ranging, he never seems to get off the fence) - but it's probably better for marketers and managers who are actually making business decisions.