For Airbnb, the key metric representing value is bookings and stays, not just searches.

In a marketplace like Airbnb, you have two types of users: guests and hosts. To measure success, you need a metric that reflects value for both groups, such as the number of nights booked.

Airbnb aims for users to stay at rental properties at least once a year, while Facebook wants users to engage with their newsfeed daily or monthly to avoid being considered churned.

Retention periods depend on the type of business; for example, an Airbnb would expect users to return based on travel frequency, which can vary widely.

Returning usage is a key indicator of product success; track how many users return within various time frames after signing up.

Airbnb is the first online marketplace that lets travelers book rooms with locals instead of hotels, which is concise and descriptive, allowing investors to understand what they're building and gauge their excitement.

The initial idea for Airbnb was to enhance the entire travel experience, not just provide a place to stay, by considering services like airport pickups and breakfast. We always intended to understand the operation of Airbnb from the inside out, including the timing and logistics of photographing apartments.

Your primary metric must capture whether your product provides recurring or enduring value to users, such as monthly recurring revenue for SaaS tools.

When you launch your company, you hope to see hockey stick growth in the first year, which is what we experienced at Airbnb with the number of guests booking through our platform.