The thing that people don't understand about positioning is that positioning is something that happens in the mind of the customer - not something that is given to the customer as a fact. The customer will take everything your company stands for, maybe a thing their friend said, what they personally feel - then make their decision. After that they will rationalize it and defend what they decided.
It is our job to provide clear signals, a clear promise and keep that promise over and over again. This is the only way we can consistently position in the customers mind and stay in the same place on the point of the gird that we want to be on.