I once read in an article (that I unfortunately can't find right now) that the the worth of Shazam lies in the fact that it can recognise, which songs are trending. The value chain is approximately like this:

1)New song is released

2)It starts being "shazamed" by various people - it's becoming trendy

3)Large stores that differntiate themselves by being trendy want to play trendy songs first

4)They pay Shazam to tell them which songs are trendy

5)The stores play them

6)Customers "shazam" those songs in the store

7)Customers view the store as trendy

8)Now four instances have profited: Shazam, the store, the musician and the customers (for having found a trendy song very early on)