The marketing plan is the overview of multi_channel approaches you should be implementing to develop and retain your prospects. It may include a call for brand development and demand generation as well. If your existing strategy is somewhat successful, but you want to grow _ the marketing services it recommends may be more focused on customer relations _ such as social media marketing, email marketing and telemarketing services.
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?