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.
A good business plan would document short-term and long-term goals of the business and establish specific tasks for achieving theses goals. Planning is the process that never ends for a business and is extremely important in the early stages of the business. However, business planning and is extremely important in the early stages of the business.
However, business planning is an ongoing process and it should be updated regularly to assist in forward planning, the challenge for the entrepreneur while preparing a business plan is to communicate his ideas and identify gaps in management information about their business, competitors and the market.
When I have received business plans, the very best responses come from people who have looked at the risks and have an answer for every question. What you never want is to throw a scenario at your plan and have to answer "I don't know what I would do in that situation". You want to plan for every possible contingency, and certainly all the major risks to the ongoing success of your business.