Understanding what works in marketing campaigns and the financial return therein is important. Marketers can use this information to justify their investment. The only way to truly understand return on marketing investment, however, is to measure consumer response to targeted marketing campaigns. So, the analytical test design of the campaign is implemented to set the stage for results measurement. The test design may be either a test-and-control design or a multivariate test design depending on business need. From there, the Analytic Cycle continues as marketers update and adapt their consumer understanding using information from what has worked in past campaigns. By creating a test and learn environment aligned with the scientific method, marketers can make better business decisions and continuously improve ROI. All thanks to a little science.