What is the best data driven argument Heather Yates can make to justify charging Windham Pharmaceuticals for impressions instead of click-throughs? (In other words, how can Heather Yates convince Windham Pharmaceuticals to stick with MedNet rather than take their advertising dollar to Marvel?) In answering this question, please make use of the quantitative information provided in the case (including in the exhibits at the end of the case); your answer should consider Profit or ROI to make a case.