The NielsenMediumMetrics00:00

Welcome to your interview for the Account Executive role at The Nielsen.
The question is on your right: Key Metrics for Media Buyers. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen. You have three graded attempts to score 7/10 or better.
What metrics do you believe are most important to media buyers and advertisers today, and why?