Another Brand Formula.
I finally met Faris last night and in a brief conversation in a bar full of international advertising types, we found that we agreed that the primary goal of marketers (not marketeers) should be to avoid disappointing and/or annoying the customer. That doesn't mean aiming low, it just means you must deliver at least what you promise.
In that vein, I would tweak Seth's definition of a brand.
Brand = [Prediction of what to expect] times [emotional power of that expectation]
Brand = Expected Performance x (1 - Disappointment Experienced)
It's a subtle change which no doubt reflects his optimism and my cynicism, but I am just not convinced that people are wowed by the vast majority of products/services to which they have some degree of loyalty. They're just happy not to be disappointed.