Key Elements of Marketing Planning that Contribute to the Success of the Planning Process

What are the key elements of marketing planning that contribute to the success of the planning process?
"Marketing is the delivery of customer satisfaction at a profit. The goal of marketing is to attract new customers by promising superior value, and to keep current customers by delivering satisfaction."(P.Kotler, Principles of marketing, 2nd ed, 1999, pg xvi.)
It's for this reason marketing planning is considered important by many theorists. As suggested by MacDonald Marketing planning, and its principle focus, is all about identifying and developing a competitive advantage in the market. Marketing planning is simply a series of events leading toward the setting of marketing objectives and plans to reach the objectives set (Macdonald 1984). It's at this stage that things such as the company's mission and vision will be identified. Strategies employed to achieve these will be a key element towards the planning process.
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