The plan should cover one year. For small companies, this is often the best way to think about marketing. Things change, people leave, markets evolve, customers come and go. Later on we suggest creating a section of your plan that addresses the medium-term future--two to four years down the road. But the bulk of your plan should focus on the coming year.
Running a business certainly can not be separated from the purpose of doing business is to achieve profit. In an effort to achieve profit, have you had a good marketing plan? Or it turns out your business is running in place without any clear management.