As far as brand fidelity, I don’t look at the brands when I grocery shop. I just look at the cheapest products, no matter what the brand name, and purchase them.
Regarding brands, I wrote the following article entitled “The Problem of Brand Conditioning” that looks at the contrast between different religious “brands” and the Lord’s church:
http://mbriley.preachersfiles.com/2009/02/28/the-problem-of-brand-conditioning/