I always find myself humming the tune of a song i've recently heard. Not knowing the name or artist I scour the internet for clues using a few of the lyrics I managed to pick up. The majority of these songs aren't the usual records produced by popular singers that dominate the charts, but instead are soundtracks cleverly used within advertising campaigns to sell their brand.
I came across a commercial the other day that instantly grabbed my attention through the use of the music...
You might say the advert is successful due to the famous faces featured (David Beckham, Agyness Deyn and Noel Gallagher) but if you were to hear it with no visual image I'm sure you would engage. Thinking back to other TV commercials that were highly successful from their soundtrack, Levi's as a brand are a good example of this...
In response to the question, I believe a cleverly chosen 'catchy' soundtrack can sell a brand.