Companies founded by a group of engineers often have a deep-seated mistrust of sales -- or more precisely, salespeople. That was the case at GitHub, says CEO and co-founder Chris Wanstrath: It wasn't until their customers started asking for a sales organization to help guide them that Wanstrath and the GitHub team realized sales wasn't necessarily filled with the fast-talking stereotypes they were used to seeing on TV. Wanstrath joins a16z General Partner Peter Levine to discuss how GitHub finally embraced sales, why good salespeople are like good teachers, and what it takes to sell to developers.