Final answer:
a) Regression analysis should be used by marketers to analyze ROI for media, as it allows for a detailed understanding of the relationships between multiple factors and the measuring effect.
Step-by-step explanation:
When a marketer wants to analyze the return on investment (ROI) for media, besides attribution, they should use regression analysis. Regression analysis is a statistical method used to determine the strength and direction of the relationship between a dependent variable (effect) and one or more independent variables (causes).
For instance, a marketer might use regression analysis to understand not only if an increase in advertising budget correlates with higher sales but also how other factors like seasonality, competition, or product changes contribute to sales figures. This involves identifying variables, drawing a scatter plot, using regression to find the line of best fit, calculating the correlation coefficient, and interpreting its significance to determine if there is a linear relationship between the variables.
Regression analysis is important because it allows for a more nuanced understanding of how different factors impact the ROI. It can offer insights that help optimize marketing strategies by allocating resources more effectively.