To me the most important secret is "If you want to make something 10 times cheaper, remove 90 percent of the material. If you look at products and think about the functionality offered, you often see that most of functionalities is not really necessary. They were added over time to increase the cutomer value. But did someone really think that it is really needed and wanted by the customer. Is it perhaps just included because everyone stays in his or her thinking pattern? By removing 90 percent of the material you have to rethink. You have to overcame mental obstacles and routines. You have to ask yourself: What is needed, what is absolutely necessary? Thus, you have to reduce it to the core value.