While I was at my local coffee shop, I overheard a conversation by the two baristas. They were wondering what range of in-store music they can play. Being a huge fan of coffee shop music (especially here in Oakland), I wondered what incentives any management would have in controlling the in-store music. As always, I found behavioral science was able to quench my curiosity.
Music Can Influence Consumer Behavior
A study conducted by Professor Ronald Milliman demonstrated that it is possible to influence behavior with music. The study manipulated three conditions at a national supermarket: 1) fast tempo music, 2) slow tempo music, and 3) no music.
Effect on In-Flow Traffic
The study found the tempo of in-store music significantly affected the pace of traffic. Presence of fast-tempo music significantly increased the in-flow traffic, whereas the presence of slow-tempo music significantly slowed pace of traffic. 
Effect on Sales Volume
There was a significant difference from the effect of slow-tempo music to fast tempo-music. Average gross sales increased from 12k for the fast tempo music to 16.5k for the slow tempo music. This is a 38.2% increase! 
Adapting These Results to Your Business
The implications of these findings must be matched with the business objectives of your company. Do you wish customers to linger and perhaps purchase more in the store or to “hurry up and leave?”
A restaurant, for instance, will most likely want to speed people up, especially during lunch, when the objective is to maximize the "number of seats turned" in a very short period of time, normally about two hours or less. Playing slow tempo music in a restaurant might result in fewer seats turned and lower profit, although it could encourage return visits if customers preferred a relaxed luncheon atmosphere.