Case 3 An online advertisement linked to Nutri, a dietary supplement shop, was served to 81% of the customers on a sports enthusiast website that attracted 41,000 visits. A total of 520 clickthroughs were recorded. Nutri spent $630 on online advertising last month. One in 8 clicks resulted in a purchase. 1. What is the clickthrough rate (9%)? 2. What is the cost per impression? 3. What is the cost per mille (CPM)? 4. What is the cost per click? 5. What is the cost per order/purchase