You've got a list of stores, and a person's location. Which store is closest? You are buying ads online, and want to maximize your ROI. You have 6 types of EC

You've got a list of stores, and a person's location. Which store is closest? You are buying ads online, and want to maximize your ROI. You have 6 types of EC2 nodes you can use, and you want to pick the most efficient set for your mildly parallel work.