Marketing plans serve as the blueprints for your company's sales strategy. They lay out every detail of what's to come over the next year and may be subject to alteration or evaluation because of changes in the market. Marketing should not be set in motion and left alone, but constantly reviewed, evaluated and adjusted to suit the needs of the company and the wants of the consumer. Understanding how to judge whether your marketing plan is delivering the best possible results can save you time and money and help ensure the success of your business.