The Importance of Wearable Devices in Music Prediction

In 2011, researchers from Emory University put teenagers through an MRI machine to see how their brains reacted to music. They did make somewhat accurate predictions of a song's sales based on these brain scans. So why are the researchers choosing it to do it with this other measure that hasn't been proved in the same way? I think the key here is the wearable device component that I talked about earlier. A lot of people already own wearable devices like the ones using this study.