[laserDinosaur]

>And then you have heart rate, which may indicate an emotional response, but it can be anything else.

It could be useful for A/B testing, with the heart rate metric being the average value of your overall data.

I wonder if you could also compare WHEN the heart rate increases with the timing of the ad - for example if your ad ends with a funny punchline and your logo, seeing the heart rate spike is a good sign people are laughing at it.