A December 2017 survey of US senior ad buyers by financial services firm Cowen and Company showed Google search was held in the highest esteem when it came to ROI. Nearly half of respondents named the platform as offering the highest ROI. Facebook ranked second, named by 30% of those polled. Google and Facebook both improved their positions from last year. In 2016, the survey found that 32% of senior ad buyers thought Google search had the best ROI, while 27% chose Facebook. In 2017, no other advertising platform garnered double-digit percentages among ad buyers. Just 8% of respondents thought ad exchanges and networks had the best ROI, while Instagram and YouTube were each named by just 4% of ad buyers. Get the full story at eMarketer