Ideas _ people said the more you talk about your ideas the more refine it becomes. I think this is true. Did you ever experience when you talk to more people you generated a lot more ideas? When people give you feedback it triggers another dimension of your ideas? If you are, so where do you keep all these ideas? It should be in a marketing plan.
Imagine if you can do all these and manage all these in a marketing plan? Systematic, organized, well thought, innovative and captured all your pertinent business information, don't you find having a marketing plan is useful for your business?