Let me get right to the point. The single most powerful small business marketing tool on the planet is a marketing plan. Now before you roll your eyes and run for the hills let me clear a few things up.When I talk about a marketing plan I am not referring to those academic exercises found in college marketing books, or the templated mumbo jumbo found in business planning software. I will not be asking you to determine your share of the market today. Give me a break, share of the market, most sma.