stion 6 Needs Grading The MRK519 class is thinking about spending $90,000 on a bus shelter ad that will reach 200,000 people who are 18+ and living near the city. In particular, they want to know what method(s)/metrics they can use to assess the effect of the bus shelter campaign. They don't want to waste their money on unnecessary impressions. As a consultant, what would you advise the class