Absolutely, yes. Marketing plan helps you promote products and services to the market of your choosing. Marketing plan is the bridge that connect two shores of your business and customers. You can reach other shore without a bridge, but it makes it way faster and effective.
Marketing plan provides several important things that are a key to your success: focus, efficiency, transparency, consistency, and clarity. With a marketing plan you can clearly define a necessary goal, allocate resources according to the needs, know exactly how everything is working out, find effective patterns and understand how to improve in the future.