This is getting a bit old, but a very interesting article in the New York Times (via Brand New) cites research showing how people's personal narrative influences their behaviour. It's tempting to boil it down to perception is reality, but there's probably quite a bit more to it.
It made me think that maybe brands work in a bit the same way. As a planner in a very classical agency, I was always a bit annoyed by our lack of understanding of how an organisation as a whole conveys the brand. I believe that that good advertising springs from a brand idea, which captures the essence of a company's culture. This seems the best way to make consistent communication and convey the brand as such and not solely as an ad-idea. (I have long thought this to be the reason for Wiedens success. They seem to have learnt it with Nike, and decided to go on, and on, and on.)
Anyway, a company's history, which is incorporated as a corporate narrative, is obviously very important for the company culture, as is the leadership, procedures, etc. So, understanding this narrative is important and there are several (planning) tools for doing this. The interesting aspect, is that this theory of narratives also help explain how communication can be just as important as an internal as an external measure. Advertising and other communication can, put bluntly, reinforce an existing or create a new corporate understanding. The article cites some examples of how this works on a personal level. Maybe, after the prophesied death of advertising, agencies will reinvent themselves as brand therapists.