The short answer is: because it's the right thing to do. When you purchase a license you support the independent artists who created the music. Beyond that, music that you have not purchased (with the exception of our Free melodies) will always include subtle but unpleasant beeps that indicate that you have not licensed it. This is a common method for indicating copyrighted, unlicensed material, and anyone who hears this music will realize that it is not being used legally.