6. Why is complaining important to marketers, and how should complaints be handled? Consumers sometimes develop post-decision dissonance—a feeling of anxiety or uncertainty regarding a purchasing decision after it has been made. On occasion, they may feel regret when they perceive an unfavorable comparison between the performance of the chosen option and the performance of the unchosen options. These feelings of regret can directly influence the consumer’s intention to buy the same product in the future. Consumers can learn from experience through hypothesis testing, in which they try to confirm or disprove expectations by actually engaging in acquisition, consumption, or disposition of a product. This process is influenced by motivation, prior knowledge (familiarity), ambiguity of information, and two types of biases: the confirmation bias and overconfidence.