His notes at the end do a good job of distilling his lessons down into memorable chunks. #4 seems especially relevant to this audience:
Know your customer. Your customer is the person who gives you money in exchange for your product or service. It’s easier than you might think to get confused about this one.
Know your customer. Your customer is the person who gives you money in exchange for your product or service. It’s easier than you might think to get confused about this one.