Netflix (NASDAQ: NFLX) surprised investors when it announced plans to increase its marketing spend from $1.3 billion in 2017 to $2 billion in 2018. The reason for the decision: "because our testing results indicate this is wise," management wrote in the company's fourth-quarter letter to shareholders.In the earnings call after dropping that bombshell, CEO Reed Hastings said he expects marketing spend to decline as the service sells itself.