“Lean thinking defines value as providing benefit to the customer; anything else is waste.”
The base of the Lean Startup is to learn as fast as possible. So, instead of building a complicated product with all the features, it’s better to build something simple, a prototype, then show it to people, and learn from it. Learn from the way they use the product, what they are saying about it, etc.
In order to make it happen, it’s important to talk to customers.