Selling is a core skill. You have to know how to sell, whether it's a product, an idea, or yourself. In 2012, Basecamp CEO Jason Fried saw the results of a bottled water-selling challenge at Techstars Chicago, a bootcamp program for startups. That one-day competition is the starting point for a conversation that includes the art of negotiation, Jason's experiences selling knives, tennis rackets, and software; and other adventures in business.