Almost every artist out there really has the ONE song of theirs that becomes like their signature hit, and that's all anybody remembers them for, despite having a repetoire of other songs. I mean, do you think the average joe out there would remember these people for anything else their these hits of theirs:
Phil Collins - "In the Air Tonight" (actually one of my least favorite of his)
Whitney Houston - "I Will Always Love You"
Justin Bieber - "Baby, Baby, Baby"
Carlye Rae Jepsen - "Call Me Maybe" (justifiable, she was a relatively obscure Canadian idol before Bieber "discovered" her)
Adele - "Rollin' in the Deep"
Rick Astley - "Never Gonna Give You Up"
David Seville - "Witch Doctor"
Jim Croce - "Leroy Brown"
The 5th Dimension - "Aquarius/Let the Sunshine In"
Kool and the Kang - "Celebration"
Bachman-Turner Overdrive - "Takin' Care of Business"
Among others?
Baha Men are an example of like Bobby McFerrin: they were an extremely obscure junkanoo group that nobody noticed... then they came out with "Who Let the Dogs Out?" which became the biggest hit of theirs ever, and brought them to people's attention, then they pretty much faded back into obscurity after that.