I've written before, and often said, that a brand is not what you say it is, it's what you're customers, stakeholders and people who come in contact with you say it is. The point is that you don't control your brand any more - the market does. The best you can do is contribute to the conversation. (BTW, I am by no means the first, nor the most highly qualified to make this point, it is fast picking up consensus.)
Much has been written about Apple and the power of it's brand. Anyone who knows me knows that I'm a huge (HUGE) Apple fan. In December of 08, The Simpsons, spoofed Apple in the opening of their show. It's worth looking at because a) it's tremendously funny and b) it provides a great insight to branding.