I've only worked in advertising a few times - animated a few logos and composed a few "jingles". Without a story I have a hard time seeing the role of the music in a TV spot - what is it supposed to mean?
In this case, I was told that the CEO of New York Life had liked the score to "Fargo" and wanted something in that vein for his firm's new campaign, so I went with that instruction and used similar instrumentation. Still I admit it left me confused - why should a Scandinvian / Celtic melody and a film noir arrangement be appropriate for an insurance company?
Seven years later they were still making new spots that use the music.