 So in a very, very high level, you have this funnel. This is a very high level. It's oversimplifying things, but still it has some value in it. How people become users? You have discovery, top of the funnel. In order for people to become users, they need to discover your product. You have conversion, which means you're taking people that land on your product but are not users and you're making them users. So on eBay, for example, it could be people that land on your product. You need to convert them to buy things or in Amazon. In Facebook case, in users land on your product, you need to make sure they log in or register. So that's conversion. And then you have retention, which means you need to keep the users using the product. And those users that fall off this funnel do not retain. You want to convert them. You want to resurrect them, sorry. And when you resurrect them, you want to convert them again because sometimes they're not using a product. So let's say somebody didn't use eBay or Amazon for a long time and you managed to bring them back to Amazon, you're still going to convert them. So when you understand this funnel, you can start thinking about tactics and products to grow each part of it.