Welcome to week four, everyone. This is the week where we concentrate on different topics related to selling through channel intermediaries. What does a channel intermediary mean? That means you don't always sell directly to consumers, you have to sell through someone else. And sometimes problems arise when that happens. For example in our first topic, the basics of double marginalization, the person we're selling through is also going to take a margin, not just us. So we have to take into account how they're thinking about margin when we set our own price. And then after we discuss double marginalization, my colleague Yael is going to be back and talk to you about the time value of money and how to calculate it. Why is that important? It's important for that third bullet point in front of you, customer lifetime value. That's a staple metric of direct marketing. Companies like Amazon who do sell directly to consumers. They need to calculate how valuable is a customer to them. And then Thomas is going to be back and talk about some techniques for setting price in different kind of industrial situations. He's going to talk about marginal cost plus pricing, which is common in the airline industry. Peak-load pricing, which is getting more popular. You might think of an example like Uber, right? They do peak-load pricing. And finally, index-based pricing. And then, at the end of the week, we're going to wrap all of that together, and we're going to do a real world case called Retail Relay, that is delivering groceries to consumers. Now, what are you going to be able to do at the end of this module? You're going to be able to define double marginalization and explain its impact on pricing. You're going to be able to calculate the time value of money. And by the way, that's not just good for pricing, it's good in a lot of other business situations as well. And you're going to be able to measure customer lifetime value and use it to determine how much marketing spending you should do to get, to retain, to acquire a given customer. You're also going to be able to describe the advantages and disadvantages of various pricing methods, and recognize when to use them. When should you really take this one versus the other one? When should you use marginal cost plus pricing? When should you use peak-load pricing, or index-based pricing? And, finally you're going to apply all this knowledge of channeling and direct to consumer pricing in a real world case.