Ha, it's funny you say that considering it's my favorite track too alongside the title track. I think we may generally have similar taste.
Edit - Actually, this was my introduction to Soul music, and I really dug it. Do you have any recommendations of where to go next?
You're in for a hell of a listening experience. ( ) is one of my favorite albums ever recorded.
If they weren't popular, would you like them, or do you just find them boring overall?