One of several important figures marketers must know is Return on Investment. Rol% measures the relationship between how much you spend on marketing activities and how much money they generate. This is a simple ngure to learn because all that is needed is Revenue. Advertising Costs the ability to subtract, divide and multiply. Let's say one of your marketing campaigns has generated 328943 revenue over the past year and the total marketing dollars spent on social media campaign comes to 5 171182 Answer example will be: 33 not 3396