Genchi Gembatsu - Go Out and Talk to Customers
Genchi Gembatsu is one of the core principles of Lean Manufacturing and is a Japanese term used at Toyota, meaning "go out and see for yourself". In other words, business decisions should always be based on firsthand knowledge (from customers)
. It is the idea that to really understand any part of any business problem, you need to go and see for yourself firsthand. You should never take anything for granted or rely solely on reports from others.
According to Ries in "The Lean Startup" it is also very important for entrepreneurs and startups to test their early vision, strategy and the key assumptions behind it by talking to and getting feedback from (potential) customers. You can use these customer interactions to sketch / draft a target customer profile to build the first, minimum viable product and to guide future product development decisions.
After you have built the first Minimum Viable Product, go and talk to customers yourself again and adjust the product and the profile.
So Genchi Gembatsu!