Cable TV and MTV were a relatively new phenomenon, and so pretty much anything with a cool video clip came by ever so often, and it generated a lot of buzz. The clip for 'Hello' was sappy and romantic, which made it popular -- and because the song was popular, the clip was shown often, creating some sort of positive feedback loop to propell the song into absolute hitdom.
I think I once slow-danced to this song during a party, with a very popular girl from my class when I was in my first year of VWO... But I might be mistaken, because thinking back I wonder how the hell that could have happened.
In the clip, Lionel Richie pines for a blind girl from a distance. She is a sculptor, and she sculpts a perfect rendition of Lionel's face with clay -- from merely running her hands over his face once!
The time had come to conduct a scientific enquiry as to the plausibility of the events portrayed in the video clip! A group of sculptors were shown a photograph of '84-era Lionel and then blindfolded. They had to sculpt Lionel's face, with the song on repeat on a CD player: The Hello Experiment.