For me it sort of depends on what exactly I'm purchasing.

I have some of my favourite brands for certain items - shampoo, deodorants etc ...

But when it comes to some food items I'm willing to try competition (biscuits, breakfast cereal, crisps etc).

When it comes to things like shoes I'm not really brand loyal I'm more "store loyal" - and they can stock a number of different brands ... whatever looks good with my outfit, I guess