Marketing and Sales are two sides of the same coin. You market your business to get your name out in front of your prospects. It starts with a plan, which is implemented over time and feeds the sales process.
Sales, on the other hand, is the direct interaction with prospects to try to get the business.
Marketing requires a broad vision, understanding your prospects as a group and understanding their habits. It is vital to separate what you want to know from what they want to know. With all the ways there are for people to be inundated with information, you have to rise to the top. Your marketing is what gets you the attention you need.
Once the marketing has done its job, the sales processes kick in. This is where you meet the client one on one and close the deal. Most small businesses can sell their product or service once they get in front of people, but it is the marketing that is more difficult for them.