Here's a bizarre anecdote: apparently Jenny Lewis was approached by Kanye West and... well, let's let her tell her story:
We missed our flight and had to wait a couple of hours in the lounge. I noticed Kanye West was waiting for the same flight. He looked over and said, 'Excuse me, would you mind listening to my new track?' And so he put his headphones on my head and I listened to two of his new songs. He had no idea who I was. I guess he was doing research.
My mate Lincoln was once asked what he thought of the new style Coke cans, back when the shift from detachable ringpulls was being made - they paid him for his time by letting him finish the can of Coke for free; and I once spent some time on the top floor of Hepworth chambers sampling sandwich pickles, but I've never heard of an artist carrying out their own market research before.
I say "carrying out their own market research"; unlike Jenny, I suspect the question was not 'how does this track resonate with a non-core audience' so much as 'will confirming that, yes, I am Kanye West persuade this attractive young lady to fling herself at me'.
If I was a pop star, though, I think I'd adopt this approach for a laugh - imagine if, say, Paul Heaton came up to you on Piccadilly station and got you to listen to a track which had, halfway through, someone whispering 'everyone on the station thinks you are Paul Heaton's boyfriend'.
[Again, thanks to Michael M]