 Okay, let's think about this. Why is it that everyone remembers hundreds of songs, almost note for note, they never set out to memorize? That's the power of sound. It's sticky. When you hear something week after week, it gets into your long-term memory even when you don't intend it to. You remember it because you heard it. That's why radio is the sticky advertising medium. You don't hear a newspaper or billboard, and really, not a web page or a Facebook ad.