Marketers are under increasing pressure to be accountable for their media investments. But it's difficult to measure programmatic top-of-funnel performance, and even harder to connect upper-funnel campaigns to bottom-line results. Less than 20 percent of marketing executives understand how their brand-building campaigns are performing, according to McKinsey & Co. Developing a holistic set of performance metrics and relevant key performance indicators (KPIs) is a critical skill which you'll need to prove to clients that your full-funnel media strategy is working.