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 successful project report must achieve the following objectives: Be appropriately arranged, with an executive summery, a table of contents and its chapters in correct order ; Be the right length and have the right appearance ; Give a sense of what you and your company expect to accomplish ; Explain in quantitative and qualitative terms, the benefits to the user of your company products and services ; Present hard evidence of the marketability of the products and services.
Before the preparing the plan, the entrepreneur should: Review previous business plans (if any) and their outcome. This review will help highlight which areas of the business have proved difficult to forecast historically. Be very clear as to objectives on which their plans will be based. Set out the key business assumptions on which their plans will be based.
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.