Example 1: You provide general marketing services and then create a marketing workbook which you sell as a product. You do not need a separate license to sell the workbook, although you will have to register with the local authorities to collect sales tax on the product.
Example 2: You are selling someone else's marketing materials as the product. You will need to work out a license agreement with the company providing you with the materials, but it is not a license that has to be registered with the state.
Example 3: You provide nursing services. You want to sell pharmaceutical products. You may well need a separate license to sell the products.
Check with an attorney who specializes in your industry area.