When the cream of the creative agencies gather in the south of France next month for the Cannes Lions, many of the awards being handed out will focus mostly on creativity. Many of the best ads evoke some sort of emotional reaction, but it can be hard to pin-point which emotions actually drive sales. For example, do you feel more affinity for the brand that makes you laugh, or for those who tell you a sad story that makes you reflect on something? RealEyes, an emotional measurement company, have started to look at the correlation between how we feel during an ad, and how it affects our purchasing intent. Here Mihkel Jäätma, CEO at RealEyes, explains how they do it and provides some background on the trials they have been running in conjunction with Mars.