It may seem like good apps or services sell themselves. That's what the whole viral thing is all about, right? Wrong, says Daniel Shapero, who helped build LinkedIn's enterprise sales team from a small core group to more than 1,200 people all over the globe. Shapero joins a16z General Partner Peter Levine (an engineer who jumped into sales before taking on his first CEO gig, and who now also teaches a class on the topic at Stanford) to discuss the right way to build a sales organization -- from answering the basic question of why sales?, to hiring, compensation ... and the inevitable culture clash that occurs when salespeople and engineers meet.