Still number one after all these years, and with good reason, YOU is the most powerful word in advertising for a reason—it's personal. Let's talk about you. You are interesting, and you find yourself interesting. Let's be honest, when it comes to you, you're all ears. If I make a promise to make people rich, you may be interested. If I promise to make YOU rich, that's a different story. You is a word that must be used when talking to your customers, because that's who you're addressing. And when you do that, you're talking about a person's favorite subject. It's so powerful, many writers (especially in direct response ) will not use a headline unless it has you in the title. I wouldn't go that far, but you is definitely something that YOU should always consider.