Some interesting thoughts and some way off topic and indeed meant for another forum.
How and why you get married is beyond the scope of this discussion.
Married to the Brand is of course all related on personal experience , how can it not be. I don't thing most of us are swayed by marketing otherwise we would all own Ronco and K-Tel products (ha dating myself somewhat) or all the single people would be calling into those late night chat phone numbers where all the girls look like Megan Fox (there a more recent reference).
The opposite side for me , for example for computers I have had both an Acer and Asus die on me before it's time. The Acer LCD flaked out about 6 minutes after the warranty expired and the Asus was about 6 months after purchase (and as luck would have it I was leaving the country for a few weeks so I absolutely needed a computer so I had to buy another one). So this turned me off these companies permanently , others may have had great experiences with those companies.
I shop at Costco and Sears part of the reason is their return policy and the customer experience I received. We bought a "Sleeping System" (yes that was what the saleslady called it ,to justify the cost I suppose
) many years ago from Sears. When they delivered it , it was the wrong mattress., We called and the next day the right mattress appeared as well as $150 certificate for our inconvenience , impressed me. A Similiar story for a local airline (WestJet - big props pun intended). We had a a bit of a Cluster &#^# on one of our flights, I complained and they responded. A lot of companies just don't get that. Good customer service will bring you back (at least me).
And I agree there is a difference between Married to the Brand vs Preference. I interpret Married to the Brand as a Loyal commitment to the point it is always your first choice and you will make an effort to get that product even if a competing product is more readily accessible.