He makes a few key points, including the importance of non-conscious learning to drive everyday decisions (it turns out that people who can only make conscious, rational decisions are pretty much incapable of functioning), the powerful influence of irrelevant facts (for example, being exposed to a random number influences the price you’re willing to pay for an unrelated object), and the need to suppress emotion when faced with a truly unprecedented problem (because your previous experience is irrelevant). Selecting software (or marketing approaches) falls into the same category.