Yesterday, I was invited to a London Business School marketing seminar at which Professor Leonard Lee presented a paper he's co-authored with On Amir and Dan Ariely (of Predictably Irrational fame).
There was a lot of arcane discussion about statistical error and its constituent parts (an hour in, we were still debating the introductory slides). But the upshot was further confirmation that people make more consistent choices when they are emotionally rather than cognitively stimulated.
In marketing terms, that means you will invoke greater loyalty if you can engage your customers emotionally. In turn, that has led to companies trying to evoke warm emotional reactions while barely mentioning their product/service and potential customers gawping incomprehendingly.
The really difficult part is generating an emotional reaction that is irrevocably tied to your product/service. It can't be an afterthought. It has to be intrinsic to everything you do.