A customer buys X from "brand A" and has positive experience with it. "Brand A" also sells Y. Now the customer things it is good to buy Y because of his/her positive experience with buying X from brand A and that since it was good, buying Y from brand A should also be good. They bought Y because of association.
What would be the name of the psychological process or cognitive bias that lead the customer to buy Y ?
It's called the Halo Effect:
The halo effect is a ... cognitive bias, where a person making an initial assessment of another person, place, or thing will assume ambiguous information based upon concrete information.
The term halo effect is used in marketing to explain customer bias toward certain products because of favorable experience with other products made by the same company. ... A notable example is the manner in which the popularity of Apple’s iPod generated enthusiasm for the corporation's other products.
