For any organization, various functional plans-marketing, financial, human resources, production-have to be laid down, even though all the functional plans serve different purposes and all theses plans provide guidance and structure to the successful running of the business.
Planning is the first and the most crucial step for starting a business. Business Planning lays down step-by-step procedure by which would function. The various functional requirements of business-marketing, finance, human resource and production, provide information to all the concerned people like employees, venture capitalists, etc. and it also draws a read map to help the entrepreneur run the business successfully.
It is known to be the most crucial step in the successful running of the business because a well planned business venture carefully scans all the possible opportunities and threats, understand the demands of the market and arranges for the best possible resources which finally lead to the success of the business.
It seems to have been put there to fill the need to attribute a certain sum to marketing. Make sure you are researching each point of your budget, make sure that you are giving it context and it makes proper sense within your overall plan.