I can't think of ANY business that won't benifit from better marketing. Go after the market you feel is best suited for you and then give them the type of introduction that will stay in their minds.
Generally .....a 5 imnutes demo is more than enough to make an impression. Any more and they won't have time to listen to it.

A nice picture, a short CD and a bio, some bus cards and you're set to go !