When this type of essay, the candidate has to make it clear to the admission committee why an MBA is a crucial step for him in order to achieve his career goals.
Mainly you need to explain:
- What skills you still lack in order to achieve your stated goals, and how the MBA/school will enable you to get each of these skills?
- What knowledge do you still lack in order to achieve your stated goals? Will the MBA enable you to get this knowledge? For example: I still lack knowledge of X to achieve my goal Y.
- What else do you still lack in order to achieve your stated goals? Experience? Contacts? How will the MBA enable you to get these things?
Your candidacy is likely to be stronger if you are more specific about what it is exactly that you are lacking in light of your goals. For instance, what exactly within marketing do you need to achieve your stated goals? Positioning? Distribution? Advertising? Strategy? Pricing? Etc.