Consider a business like eBay. For every 1 seller joining eBay, another 5 buyers are willing to join. For every 10 buyers joining eBay, another 1 seller is willing to join. Once they have joined the platform, the churn rate among buyers is 80% (4 of every 5 doesn't come back next year) while the churn rate among sellers is 50% (1 out of every 2 doesn't come back next year). The platform earns $10 in profit from each seller and $1 in profit from each buyer every year. For simplicity, ignore discounting across periods. a) What is the lifetime value of a seller? (2 points) b) What is the lifetime value of a buyer? (2 points) c) The platform can invest in increasing buyer stickiness or seller stickiness. If the platform invests in increasing buyer stickiness, the churn rate among buyers will reduce to 50%. If the platform invests in increasing seller stickiness, the churn rate among sellers will reduce to 25%. Assuming that the platform has budget constraints and therefore can only invest in user stickiness on one side of the market, which side should the platform invest in? (2 points)