Final answer:
Jill's disregard for the perpetual 30% store discount is an example of 'adaptation', wherein she has become desensitized to this marketing strategy.
Step-by-step explanation:
Jill's behavior in becoming accustomed to the 30% discount and no longer paying attention to it is an example of adaptation. Adaptation in a consumer context refers to the process by which consumers become desensitized to marketing stimuli such as perpetual discounts. When a discount or promotional offer becomes a norm, consumers may no longer perceive it as a special deal, resulting in a diminishment of its effectiveness as a sales strategy.