# 50. Self-delusion - the manipulation of self ## 50.5. Methodology/Refinements/Sub-species ### 50.5.16. Buyer's Stockholm syndrome Also known as "Post-purchase rationalisation", is the self-delusion whereby someone who buys an expensive product or service overlooks any faults or defects in order to justify their purchase. Many purchasing decisions are made emotionally, based on factors such as brand-loyalty and advertising pressures, and so these buying decisions are often rationalized retrospectively in an attempt to justify the choice. When a person has clearly made a poor purchasing decision, they will still attempt to justify the decision by trying to convince themselves and their peers that it was a good decision. This rationalization is based on the so-called "Principle of Commitment" and the psychological desire to stay consistent to that commitment. It is related to the concept of loss aversion where the victim cannot face the possibility that they have made a wasteful purchase. So, they create an artificial reality to justify the bad decision. The phenomenon is well known to marketers who rely on slick marketing and image to persuade customers to buy their product, knowing that any shortfall in product quality, value or usefulness will be made up for by the buyer's insistence that it was a good purchase. Victims of this manipulation actually become instrumental in the plot of the manipulator by aggressively promoting the product as a means of justifying their own bad decision.